tag:theconversation.com,2011:/ca/topics/ocean-garbage-patches-12165/articlesocean garbage patches – The Conversation2023-07-12T20:04:25Ztag:theconversation.com,2011:article/2094872023-07-12T20:04:25Z2023-07-12T20:04:25Z‘Humanity’s signature’: study finds plastic pollution in the world’s lakes can be worse than in oceans<p>A world-first study has found concentrations of plastics in some lakes are higher than in the most contaminated parts of oceans, demonstrating the extent to which plastics have invaded Earth’s ecosystems.</p>
<p>In a study <a href="https://www.nature.com/articles/s41586-023-06168-4">released today</a>, researchers sampled 38 lakes and reservoirs around the world, including in Australia, the United States, United Kingdom and Europe. Plastics and microplastics were found at every site, including very remote locations.</p>
<p>Lakes are sentinels for human activity. Many lakes are already suffering from issues such as algal blooms, deoxygenation, over-extraction and drying. Plastic contamination adds yet another threat to these highly stressed ecosystems.</p>
<h2>The plastics problem</h2>
<p>After plastics enter the environment, they generally break up and become smaller and smaller. Eventually they become microplastics – defined as particles less than 5 mm in size. </p>
<p>Plastic takes decades to disappear. It can <a href="https://oceanservice.noaa.gov/facts/microplastics.html">harm</a> ocean and aquatic life and contaminate water used by humans. </p>
<p>Plastics can be washed into lakes from the adjacent land areas. Lake water can sit for a long time without being flushed out, allowing plastics to accumulate.
We don’t yet know much about whether microplastics are absorbed by filter feeding organisms such as clams, mussels and zooplankton, and how plastics affect the food chain.</p>
<p>Plastic debris is widespread in freshwater ecosystems. But much of the focus has been on marine ecosystems, and knowledge of the scope of the problem in lakes and reservoirs has been hampered by a lack of appropriate data. Our research set out to close this gap.</p>
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Read more:
<a href="https://theconversation.com/plastic-pollution-threatens-birds-far-out-at-sea-new-research-209081">Plastic pollution threatens birds far out at sea – new research</a>
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<h2>What we did</h2>
<p>A global team of scientists, of which we were part, examined the abundance and type of plastic debris in freshwater ecosystems. Surface waters were sampled in 38 lakes and reservoirs across 23 countries (mostly in the Northern Hemisphere) and six continents.</p>
<p>Importantly, we used a standardised collection and analysis method, including very fine plankton nets to sample the plastic debris. These steps allowed for comparisons between lakes. </p>
<p>Broadly, we found plastic debris in all lakes studied. Most plastics were in the microplastic size range. However, concentrations varied widely. </p>
<p>Some 21 lakes had low concentrations – below one particle per cubic metre (m³). Of the remainder, 14 lakes had concentrations between one and five particles per m³ and three lakes had concentrations higher than five particles per m³.</p>
<p><a href="https://en.wikipedia.org/wiki/Forest_Lake,_Queensland">Forest Lake</a> in Brisbane was the Australian study site. It’s a popular urban lake used by many people for recreation. This lake had three plastics particles per cubic metre, ranking it sixth worst among the 38 lakes sampled. </p>
<p>The three most polluted lakes were, in order, Lake Lugano (Switzerland, Italy), Lake Maggiore (Italy) and Lake Tahoe (US). </p>
<p>In each of these lakes, plastic concentrations reached or exceeded those in “floating garbage patches” – marine areas collecting large amounts of debris, such as the <a href="https://education.nationalgeographic.org/resource/great-pacific-garbage-patch/">Great Pacific Garbage Patch</a>. These ocean areas were previously thought to be the worst cases of plastic pollution in water environments. </p>
<p>These three polluted lakes – as well as the heavily contaminated Lough Neagh in Northern Ireland – are also important sources of drinking water for local communities.</p>
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Read more:
<a href="https://theconversation.com/whales-and-dolphins-found-in-the-great-pacific-garbage-patch-for-the-first-time-122538">Whales and dolphins found in the Great Pacific Garbage Patch for the first time</a>
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<img alt="hands sorting plastic debris" src="https://images.theconversation.com/files/536750/original/file-20230711-17-y5zzsa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/536750/original/file-20230711-17-y5zzsa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/536750/original/file-20230711-17-y5zzsa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/536750/original/file-20230711-17-y5zzsa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/536750/original/file-20230711-17-y5zzsa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/536750/original/file-20230711-17-y5zzsa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/536750/original/file-20230711-17-y5zzsa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">A crew sorting plastic debris collected from the Great Pacific Garbage Patch in 2019.</span>
<span class="attribution"><span class="source">The Ocean Cleanup</span></span>
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<h2>Where is the plastic coming from?</h2>
<p>The second part of our study sought to identify the landscape factors affecting the abundance and type of plastic debris.</p>
<p>More than 90% of the plastic particles belonged to two shape categories: fibres and fragments. We even found textile fibres in lakes and reservoirs in remote areas with limited human presence, such as Avery Lake in the US state of Michigan.</p>
<p>Our analysis indicated two types of lake are particularly vulnerable to plastic contamination: those in highly urbanised and populated areas, and those with a large surface area.</p>
<p>The most common colour of plastic particle was black (30%), followed by transparent (24%), blue (18%) and white (13%). The low concentrations of particles in bright colours, such as red, suggests these more visible plastics may have been mistaken by aquatic organisms for food, and ingested.</p>
<h2>So what next?</h2>
<p>Marine environments are generally considered the final resting place for plastic debris. But our research confirms plastic concentrations in freshwater ecosystems can be higher than those in oceans. </p>
<p>Our results indicate that lakes play a major role in the global plastic cycle. This points to an urgent need to develop management policies to reduce plastic pollution in freshwater lakes. This, in turn, will help prevent plastics from entering waterways and ending up in marine systems.</p>
<p>We don’t know how much plastic debris ends up in water supplies. We suggest this gap be addressed as soon as possible, and the ecological harm caused by microplastics should become a global management and research priority.</p>
<p>Our study also underscores the urgent need for coordinated, systematic monitoring of plastic pollution.</p>
<p>Sadly, it seems no lake can be considered truly “pristine” with respect to plastic pollution. Our research serves as yet another unfortunate reminder of humanity’s indelible signature on nature. </p>
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Read more:
<a href="https://theconversation.com/we-have-no-idea-how-much-microplastic-is-in-australias-soil-but-it-could-be-a-lot-96858">We have no idea how much microplastic is in Australia's soil (but it could be a lot)</a>
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<img src="https://counter.theconversation.com/content/209487/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Hamilton receives funding from the Australian Research Council.</span></em></p><p class="fine-print"><em><span>Deniz Özkundakci received funding from the Bay of Plenty Regional Council. He also holds the Toihuarewa Waimāori - Bay of Plenty Regional Council Chair in Lake and Freshwater Science
</span></em></p><p class="fine-print"><em><span>Mohammadhassan Ranjbar receives funding from the Australian Research Council. </span></em></p><p class="fine-print"><em><span>Justin Brookes does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Researchers even found textile fibres in very remote lakes with limited human presence.David Hamilton, Director, Australian Rivers Institute, Griffith UniversityDeniz Özkundakci, Associate Professor of Lake and Freshwater Science, University of WaikatoJustin Brookes, Director, Water Research Centre, University of AdelaideMohammad Hassan Ranjbar, Research Fellow, Griffith UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1728482021-12-03T19:34:28Z2021-12-03T19:34:28ZPlastic trash in the ocean is a global problem, and the US is the top source – a new report urges action<figure><img src="https://images.theconversation.com/files/435428/original/file-20211202-21915-1bvno5s.jpg?ixlib=rb-1.1.0&rect=69%2C0%2C3730%2C2578&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Plastic debris on a beach on Lanai, a sparsely populated Hawaiian island.</span> <span class="attribution"><span class="source">Matthew Koller</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>Plastic waste of all shapes and sizes permeates the world’s oceans. It shows up on <a href="https://www.nationalgeographic.com/environment/article/beach-cleanups-missing-millions-of-plastic-pieces">beaches</a>, in <a href="https://theconversation.com/hundreds-of-fish-species-including-many-that-humans-eat-are-consuming-plastic-154634">fish</a> and even in <a href="https://doi.org/10.1038/s41467-018-03825-5">Arctic sea ice</a>. And a <a href="https://www.nap.edu/resource/other/dels/plastics-in-the-ocean/">new report</a> from the National Academies of Sciences, Engineering, and Medicine makes clear that the U.S. is a big part of the problem. </p>
<p>As the report shows, the U.S. produces a large share of the global supply of plastic resin – the precursor material to all plastic industrial and consumer products. It also imports and exports billions of dollars’ worth of plastic products every year. </p>
<p>On a per capita basis, the U.S. produces an order of magnitude more plastic waste than China – a nation often vilified over pollution-related issues. These findings build off a study published in 2020 that concluded that the U.S. is the <a href="http://dx.doi.org/10.1126/sciadv.abd0288">largest global source of plastic waste</a>, including plastics shipped to other countries that later are mismanaged. </p>
<p>And <a href="https://www.epa.gov/facts-and-figures-about-materials-waste-and-recycling/plastics-material-specific-data">only a small fraction</a> of plastic in U.S. household waste streams is recycled. The study calls current U.S. recycling systems “<a href="https://www.nap.edu/resource/26132/Ocean_Plastic_Waste_Highlights_2021.pdf">grossly insufficient</a> to manage the diversity, complexity and quantity of plastic waste.”</p>
<p>As scientists who study the <a href="https://scholar.google.com/citations?user=uo1sSBwAAAAJ&hl=en">effects of plastic pollution</a> on <a href="https://scholar.google.com/citations?user=-4sV0MEAAAAJ&hl=en">marine</a> <a href="https://scholar.google.com/citations?hl=en&user=t87Kkb8AAAAJ">ecosystems</a>, we view this report as an important first step on a long road to reducing ocean plastic pollution. While it’s important to make clear how the U.S. is contributing to ocean plastic waste, we see a need for specific, actionable goals and recommendations to mitigate the plastic pollution crisis, and would have liked to see the report go further in that direction. </p>
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<h2>Plastic is showing up in seafood</h2>
<p>Researchers started documenting marine plastic pollution in the <a href="https://doi.org/10.2307/4083505">late 1960s</a> and <a href="http://dx.doi.org/10.1126/science.175.4027.1240">early 1970s</a>. Public and scientific interest in the issue exploded in the early 2000s after <a href="https://en.wikipedia.org/wiki/Charles_J._Moore">oceanographer Charles Moore</a> drew attention to the <a href="https://www.nationalgeographic.org/encyclopedia/great-pacific-garbage-patch/">Great Pacific Garbage Patch</a> – a region in the central north Pacific where ocean currents concentrate floating plastic trash into spinning collections thousands of miles across. </p>
<p>More plastic garbage patches have now been found in <a href="https://oceanservice.noaa.gov/podcast/mar18/nop14-ocean-garbage-patches.html">the South Pacific, the North and South Atlantic, and the Indian Ocean</a>. Unsurprisingly, plastic pervades marine food webs. <a href="http://dx.doi.org/10.1126/science.abh0945">Over 700 marine species</a> are known to ingest plastic, including <a href="https://doi.org/10.1111/gcb.15533">over 200 species of fish that humans eat</a>. </p>
<p>Humans also consume plastic that <a href="https://pubs.acs.org/doi/10.1021/acs.est.9b02540">fragments into beverages</a> and food from packaging and <a href="https://doi.org/10.1021/acs.est.0c07384">inhale microplastic particles in household dust</a>. Scientists are only beginning to assess what this means for public health. Research to date suggests that exposure to plastic-associated chemicals may <a href="https://doi.org/10.1016/j.envint.2018.07.029">interfere with hormones that regulate many processes in our bodies</a>, <a href="https://doi.org/10.1016/j.envint.2020.106330">cause developmental problems in children</a>, or <a href="https://doi.org/10.3389/fendo.2021.724989">alter human metabolic processes in ways that promote obesity</a></p>
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<figcaption><span class="caption">Scientists estimate that if plastics continue to enter the ocean at current rates they will outweigh fish by 2050.</span></figcaption>
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<h2>A need for a national strategy</h2>
<p>The new report is a sweeping overview of marine plastic pollution, grounded in science. However, many of its conclusions and recommendations have been proposed in various forms for years, and in our view the report could have done more to advance those discussions.</p>
<p>For example, it strongly recommends developing a national marine debris monitoring program, led by the National Oceanographic and Atmospheric Administration’s <a href="https://marinedebris.noaa.gov">Marine Debris Program</a>. We agree with this proposal, but the report does not address what to monitor, how to do it or what the specific goals of monitoring should be.</p>
<p>Ideally, we believe the federal government should create a coalition of relevant agencies, such as NOAA, the Environmental Protection Agency and the National Institutes of Health, to tackle plastic pollution. Agencies have done this in the past in response to acute pollution events, such as the 2010 <a href="https://www.gulfspillrestoration.noaa.gov">BP Deepwater Horizon oil spill</a>, but not for chronic problems like marine debris. The report proposes a cross-government effort as well but does not provide specifics. </p>
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<a href="https://images.theconversation.com/files/435646/original/file-20211203-25-vl7p5o.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Graphic showing main types of waste collected on U.S. beaches" src="https://images.theconversation.com/files/435646/original/file-20211203-25-vl7p5o.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/435646/original/file-20211203-25-vl7p5o.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=298&fit=crop&dpr=1 600w, https://images.theconversation.com/files/435646/original/file-20211203-25-vl7p5o.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=298&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/435646/original/file-20211203-25-vl7p5o.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=298&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/435646/original/file-20211203-25-vl7p5o.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=375&fit=crop&dpr=1 754w, https://images.theconversation.com/files/435646/original/file-20211203-25-vl7p5o.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=375&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/435646/original/file-20211203-25-vl7p5o.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=375&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">In 2019 volunteers for the nonprofit Surfrider Foundation removed nearly 300,000 pounds of trash from U.S. beaches, nearly all of it plastic.</span>
<span class="attribution"><a class="source" href="https://www.surfrider.org/coastal-blog/entry/surfriders-2019-beach-cleanup-report">Surfrider Foundation</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<h2>An underfunded problem</h2>
<p>Actions to detect, track and remove plastic waste from the ocean will require substantial financial support. But there’s little federal funding for marine debris research and cleanup. In 2020, for example, NOAA’s Marine Debris Program budget request was <a href="https://www.noaa.gov/sites/default/files/legacy/document/2019/Nov/FY2020-BlueBook.pdf">$US7 million</a>, which represents 0.1% of NOAA’s $5.65B 2020 budget. Proposed funding for the Marine Debris Program <a href="https://www.noaa.gov/sites/default/files/2021-06/NOAABlueBook2022_final.pdf">increased by $9 million for fiscal 2022</a>, which is a step in the right direction.</p>
<p>Even so, making progress on ocean plastic waste will require considerably more funding for academic research, nongovernmental organizations and NOAA’s marine debris activities. Increased support for these programs will help close knowledge gaps, increase public awareness and spur effective action across the entire life cycle of plastics.</p>
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<figcaption><span class="caption">One way to address marine plastic waste is to capture it before it enters the ocean. Mr. Trash Wheel, a solar-powered semi-autonomous trash interceptor, removes floating debris from Baltimore’s Inner Harbor.</span></figcaption>
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<h2>Corporate responsibility and equity</h2>
<p>The private sector also has a crucial role to play in reducing plastic use and waste. We would have liked to see more discussion in the report of how businesses and industries contribute to the accumulation of ocean plastic waste and their role in solutions.</p>
<p>The report correctly notes that plastic pollution is an environmental justice issue. Minority and low-income communities are disproportionately affected by many activities that produce plastic waste, from <a href="https://doi.org/10.1146/annurev.energy.28.050302.105617">oil drilling emissions</a> to toxic chemicals released during the <a href="https://ej4all.org/life-at-the-fenceline">production or incineration of plastics</a>. Some proposals in the report, such as better waste management and increased recycling, may benefit these communities – but only if they are directly involved in planning and carrying them out. </p>
<p>[<em>Over 140,000 readers rely on The Conversation’s newsletters to understand the world.</em> <a href="https://memberservices.theconversation.com/newsletters/?source=inline-140ksignup">Sign up today</a>.]</p>
<p>The study also highlights the need to produce less plastic and scale up effective plastic recycling. More public and private funding for solutions like reusable and refillable containers, reduced packaging and standardized plastic recycling processes would increase opportunities for consumers to shift away from single-use disposable products. </p>
<p>Plastic pollution threatens the world’s oceans. It also poses direct and indirect risks to human health. We hope the <a href="https://www.sullivan.senate.gov/newsroom/press-releases/save-our-seas-20-lead-sponsors-welcome-new-academy-of-sciences-report-on-marine-debris-crisis">bipartisan support this study has received</a> is a sign that U.S. leaders are ready to take far-reaching action on this critical environmental problem.</p><img src="https://counter.theconversation.com/content/172848/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Matthew Savoca receives funding from the National Science Foundation and Stanford University.</span></em></p><p class="fine-print"><em><span>Anna Robuck receives funding from the European Union’s Horizon 2020 research and innovation programme under the AURORA grant agreement and the Icahn School of Medicine at Mount Sinai. </span></em></p><p class="fine-print"><em><span>Lauren Kashiwabara is a volunteer for The Marine Mammal Center. </span></em></p>An estimated 8 million metric tons of plastic waste enters the ocean each year – equivalent to dumping in a garbage truckload of it every minute. A new report calls on the US to help stem the deluge.Matthew Savoca, Postdoctoral researcher, Stanford UniversityAnna Robuck, Postdoctoral Research Fellow, Icahn School of Medicine at Mount SinaiLauren Kashiwabara, Master's Degree Student in Biological Sciences, University of the PacificLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1637092021-07-09T12:37:15Z2021-07-09T12:37:15ZThe ocean is full of tiny plastic particles – we found a way to track them with satellites<figure><img src="https://images.theconversation.com/files/410391/original/file-20210708-17-1xyjet3.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3532%2C2360&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Plastic fragments washed onto Schiavonea beach in Calabria, Italy, in a 2019 storm. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/detail-of-microplastics-along-the-schiavonea-beach-news-photo/1128486654">Alfonso Di Vincenzo/KONTROLAB /LightRocket via Getty Images</a></span></figcaption></figure><p>Plastic is the most common type of debris floating in the world’s oceans. Waves and sunlight break much of it down into smaller particles called microplastics – fragments <a href="https://oceanservice.noaa.gov/facts/microplastics.html">less than 5 millimeters across</a>, roughly the size of a sesame seed.</p>
<p>To understand how microplastic pollution is affecting the ocean, scientists need to know how much is there and where it is accumulating. Most data on microplastic concentrations comes from commercial and research ships that tow <a href="https://oceanexplorer.noaa.gov/explorations/02sab/logs/aug07/media/plnet.html">plankton nets</a> – long, cone-shaped nets with very fine mesh designed for collecting marine microorganisms.</p>
<p>But net trawling can sample only small areas and may be underestimating true plastic concentrations. Except in the <a href="https://oceanservice.noaa.gov/facts/gyre.html">North Atlantic and North Pacific gyres</a> – large zones where ocean currents rotate, collecting floating debris – scientists have done very little sampling for microplastics. And there is scant information about how these particles’ concentrations vary over time. </p>
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<a href="https://images.theconversation.com/files/410408/original/file-20210708-13-1mdrd6c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Two people lower conical nets off a research ship into the water." src="https://images.theconversation.com/files/410408/original/file-20210708-13-1mdrd6c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/410408/original/file-20210708-13-1mdrd6c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/410408/original/file-20210708-13-1mdrd6c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/410408/original/file-20210708-13-1mdrd6c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/410408/original/file-20210708-13-1mdrd6c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/410408/original/file-20210708-13-1mdrd6c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/410408/original/file-20210708-13-1mdrd6c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Researchers deploy plankton sampling nets in Lake Michigan.</span>
<span class="attribution"><a class="source" href="https://flic.kr/p/y8PcUz">NOAA</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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<p>To address these questions, University of Michigan research assistant <a href="https://www.linkedin.com/in/madeline-evans-644437159/">Madeline Evans</a> and I developed a new way to <a href="http://dx.doi.org/10.1109/TGRS.2021.3081691">detect microplastic concentrations from space</a> using NASA’s <a href="https://www.nasa.gov/cygnss">Cyclone Global Navigation Satellite System</a>. CYGNSS is a network of eight microsatellites that was launched in 2016 to help scientists predict hurricanes by analyzing tropical wind speeds. They measure how wind roughens the ocean’s surface – an indicator that we realized could also be used to detect and track large quantities of microplastics.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><strong><em>This story is part of <a href="https://theconversation.com/uk/topics/oceans-21-96784">Oceans 21</a></em></strong>
<br><em>Our series on the global ocean opened with <a href="https://oceans21.netlify.app/">five in depth profiles</a>. Look out for new articles on the state of our oceans in the lead up to the UN’s next climate conference, COP26. The series is brought to you by The Conversation’s international network.</em></p>
<h2>Looking for smooth zones</h2>
<p>Annual global production of plastic has increased every year since the 1950s, reaching <a href="https://www.statista.com/statistics/282732/global-production-of-plastics-since-1950/">359 million metric tons in 2018</a>. Much of it ends up in open, uncontrolled landfills, where it can wash into river drainage zones and ultimately into the world’s oceans. </p>
<p>Researchers first documented plastic debris in the oceans in the 1970s. Today, it accounts for an estimated <a href="https://www.iucn.org/resources/issues-briefs/marine-plastics">80% to 85% of marine litter</a>. </p>
<p>The radars on CYGNSS satellites are designed to measure winds over the ocean indirectly by measuring how they roughen the water’s surface. We knew that when there is a lot of material floating in the water, winds don’t roughen it as much. So we tried computing how much smoother measurements indicated the surface was than it should have been if winds of the same speed were blowing across clear water. </p>
<p>This anomaly – the “missing roughness” – turns out to be highly correlated with the concentration of microplastics near the ocean surface. Put another way, areas where surface waters appear to be unusually smooth frequently contain high concentrations of microplastics. The smoothness could be caused by the microplastics themselves, or possibly by something else that’s associated with them. </p>
<p>By combining all the measurements made by CYGNSS satellites as they orbit around the world, we can create global time-lapse images of ocean microplastic concentrations. Our images readily identify the <a href="https://marinedebris.noaa.gov/info/patch.html">Great Pacific Garbage Patch</a> and secondary regions of high microplastic concentration in the North Atlantic and the southern oceans. </p>
<h2>Tracking microplastic flows over time</h2>
<p>Since CYGNSS tracks wind speeds constantly, it lets us see how microplastic concentrations change over time. By <a href="https://www.youtube.com/watch?v=sQTGOU9LiJ0">animating a year’s worth of images</a>, we revealed seasonal variations that were not previously known.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/sQTGOU9LiJ0?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">This animation shows how satellite data can be used to track where microplastics enter the water, how they move and where they tend to collect.</span></figcaption>
</figure>
<p>We found that global microplastic concentrations tend to peak in the North Atlantic and Pacific during the Northern Hemisphere’s summer months. June and July, for example, are the peak months for the Great Pacific Garbage Patch. </p>
<p>Concentrations in the Southern Hemisphere peak during its summer months of January and February. Lower concentrations during the winter in both hemispheres are likely due to a combination of stronger currents that break up microplastic plumes and increased vertical mixing – the exchange between surface and deeper water – that transports some of the microplastic down below the surface.</p>
<p>This approach can also target smaller regions over shorter periods of time. For example, we examined episodic outflow events from the mouths of the China’s Yangtze and Qiantang rivers where they empty into the East China Sea. These events may have been associated with increases in industrial production activity, or with increases in the rate at which managers allowed the rivers to flow through dams. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/410485/original/file-20210708-25-1f69f2g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Satellite images, color-coded to show density of microplastic particles in the water." src="https://images.theconversation.com/files/410485/original/file-20210708-25-1f69f2g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/410485/original/file-20210708-25-1f69f2g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=353&fit=crop&dpr=1 600w, https://images.theconversation.com/files/410485/original/file-20210708-25-1f69f2g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=353&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/410485/original/file-20210708-25-1f69f2g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=353&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/410485/original/file-20210708-25-1f69f2g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=444&fit=crop&dpr=1 754w, https://images.theconversation.com/files/410485/original/file-20210708-25-1f69f2g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=444&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/410485/original/file-20210708-25-1f69f2g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=444&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">These images show microplastic concentrations (number of particles per square kilometer) at the mouths of the Yangtze and Qiantang rivers where they empty in to the East China Sea. (A) Average density year-round; (B) short-lived burst of particles from the Qiantang River; (C and D) short-lived bursts from the Yangtze River.</span>
<span class="attribution"><a class="source" href="http://dx.doi.org/10.1109/TGRS.2021.3081691">Evans and Ruf, 2021.</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Better targeting for cleanups</h2>
<p>Our research has several potential uses. Private organizations, such as <a href="https://theoceancleanup.com/about/">The Ocean Cleanup</a>, a nonprofit in The Netherlands, and <a href="https://clewat.com/en/">Clewat</a>, a Finnish company specializing in clean technology, use specially outfitted ships to collect, recycle and dispose of marine litter and debris. We have begun conversations with both groups and hope eventually to help them deploy their fleets more effectively. </p>
<p>Our spaceborne imagery may also be used to validate and improve numerical prediction models that attempt to track how microplastics move through the oceans using ocean circulation patterns. Scholars are <a href="http://dx.doi.org/10.1088/1748-9326/10/12/124006">developing several such models</a>. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/410412/original/file-20210708-21-rztaic.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Large barge with conveyor belt pulling plastic debris out of river." src="https://images.theconversation.com/files/410412/original/file-20210708-21-rztaic.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/410412/original/file-20210708-21-rztaic.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/410412/original/file-20210708-21-rztaic.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/410412/original/file-20210708-21-rztaic.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/410412/original/file-20210708-21-rztaic.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/410412/original/file-20210708-21-rztaic.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/410412/original/file-20210708-21-rztaic.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A solar-powered barge that filters plastic out of water, designed by Dutch NGO The Ocean Cleanup, deployed in the Rio Ozama, Dominican Republic, in 2020.</span>
<span class="attribution"><a class="source" href="https://theoceancleanup.com/media-gallery/#&gid=7&pid=1">The Ocean Cleanup</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>While the ocean roughness anomalies that we observed correlate strongly with microplastic concentrations, our estimates of concentration are based on the correlations that we observed, not on a known physical relationship between floating microplastics and ocean roughness. It could be that the roughness anomalies are caused by something else that is also correlated with the presence of microplastics. </p>
<p>One possibility is <a href="https://www.britannica.com/science/surfactant">surfactants</a> on the ocean surface. These liquid chemical compounds, which are widely used in detergents and other products, move through the oceans in ways similar to microplastics, and they also have a damping effect on wind-driven ocean roughening.</p>
<p>Further study is needed to identify how the smooth areas that we identified occur, and if they are caused indirectly by surfactants, to better understand exactly how their transport mechanisms are related to those of microplastics. But I hope this research can be part of a fundamental change in tracking and managing microplastic pollution.</p>
<p>[<em>The Conversation’s science, health and technology editors pick their favorite stories.</em> <a href="https://theconversation.com/us/newsletters/science-editors-picks-71/?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=science-favorite">Weekly on Wednesdays</a>.]</p><img src="https://counter.theconversation.com/content/163709/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Christopher Ruf receives funding from NASA, where he is the Principal Investigator of the CYGNSS mission.</span></em></p>New research suggests that an effective way to locate and track large concentrations of microplastics in the ocean could be from high in the sky.Christopher Ruf, Professor of Climate and Space Sciences and Engineering, University of MichiganLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1144392019-04-15T20:16:43Z2019-04-15T20:16:43ZThere’s no ‘garbage patch’ in the Southern Indian Ocean, so where does all the rubbish go?<figure><img src="https://images.theconversation.com/files/266777/original/file-20190401-177175-1wvztzj.jpg?ixlib=rb-1.1.0&rect=18%2C590%2C2066%2C1344&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Plastic waste on a remote beach in Sri Lanka.</span> <span class="attribution"><span class="license">Author provided</span></span></figcaption></figure><p>Great areas of our rubbish are known to form in parts of the Pacific and Atlantic oceans. But no such “garbage patch” has been found in the Southern Indian Ocean.</p>
<p>Our research – <a href="https://agupubs.pericles-prod.literatumonline.com/doi/pdf/10.1029/2018JC014806" title="Role of Indian Ocean Dynamics on Accumulation of Buoyant Debris">published recently in Journal of Geophysical Research: Oceans</a> – looked at why that’s the case, and what happens to the rubbish that gets dumped in this particular area.</p>
<p>Every year, up to 15 million tonnes of plastic waste is estimated to make its way into the ocean through coastlines (<a href="https://doi.org/10.1126/science.1260352" title="Plastic waste inputs from land into the ocean">about 12.5 million tonnes</a>) and rivers (<a href="https://doi.org/10.1038/ncomms15611" title="River plastic emissions to the world’s oceans">about 2.5 million tonnes</a>). This amount is expected to <a href="https://doi.org/10.1126/science.1260352" title="Plastic waste inputs from land into the ocean">double by 2025</a>.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/a-current-affair-the-movement-of-ocean-waters-around-australia-96779">A current affair: the movement of ocean waters around Australia</a>
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</em>
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<p>Some of this waste sinks in the ocean, some is washed up on beaches, and some floats on the ocean surface, transported by currents.</p>
<h2>The garbage patches</h2>
<p>As plastic materials are extremely durable, floating plastic waste can travel great distances in the ocean. Some floating plastics collect in the centre of subtropical circulating currents known as <a href="https://oceanservice.noaa.gov/facts/gyre.html">gyres</a>, between 20 to 40 degrees north and south, to create these garbage patches.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/269216/original/file-20190415-76853-1hbn7sv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/269216/original/file-20190415-76853-1hbn7sv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/269216/original/file-20190415-76853-1hbn7sv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=235&fit=crop&dpr=1 600w, https://images.theconversation.com/files/269216/original/file-20190415-76853-1hbn7sv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=235&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/269216/original/file-20190415-76853-1hbn7sv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=235&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/269216/original/file-20190415-76853-1hbn7sv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=295&fit=crop&dpr=1 754w, https://images.theconversation.com/files/269216/original/file-20190415-76853-1hbn7sv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=295&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/269216/original/file-20190415-76853-1hbn7sv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=295&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Great Pacific Garbage Patch.</span>
<span class="attribution"><a class="source" href="https://oceanservice.noaa.gov/facts/garbagepatch.html">National Oceanic and Atmospheric Administration</a></span>
</figcaption>
</figure>
<p>Here, the ocean currents converge at the centre of the gyre and sink. But the floating plastic material remains at the surface, allowing it to concentrate in these regions.</p>
<p>The best known of these garbage patches is the Great Pacific Garbage Patch, which contains about <a href="https://www.theoceancleanup.com/great-pacific-garbage-patch/">80,000 tonnes of plastic waste</a>. As the <a href="https://oceanservice.noaa.gov/facts/garbagepatch.html">National Oceanic and Atmospheric Administration points out</a>, the “patches” are not actually clumped collections of easy-to-see debris, but concentrations of litter (mostly small pieces of floating plastic).</p>
<p><div data-react-class="InstagramEmbed" data-react-props="{"url":"https://www.instagram.com/p/BNrn8c9hcX2","accessToken":"127105130696839|b4b75090c9688d81dfd245afe6052f20"}"></div></p>
<p>Similar, but smaller, patches exist in the North and South Atlantic Oceans and the South Pacific Ocean. In total, it is estimated that <a href="https://doi.org/10.1088/1748-9326/10/12/124006" title="A global inventory of small floating plastic debris">only 1% of all plastic waste that enters the ocean is trapped in the garbage patches</a>. It is still a mystery what happens to the remaining 99% of plastic waste that has entered the ocean.</p>
<h2>Rubbish in the Indian Ocean</h2>
<p>Even less is known about what happens to plastic in the Indian Ocean, although it receives the largest input of plastic material globally. </p>
<p>For example, it has been estimated that up to 90% of the <a href="https://www.theguardian.com/science/2017/nov/05/terrawatch-the-rivers-taking-plastic-to-the-oceans">global riverine input of plastic waste</a> originates from Asia. The input of plastics to the Southern Indian Ocean is mainly through Indonesia. The Australian contribution is small.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/266779/original/file-20190401-177196-i8ce4c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/266779/original/file-20190401-177196-i8ce4c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/266779/original/file-20190401-177196-i8ce4c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=360&fit=crop&dpr=1 600w, https://images.theconversation.com/files/266779/original/file-20190401-177196-i8ce4c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=360&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/266779/original/file-20190401-177196-i8ce4c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=360&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/266779/original/file-20190401-177196-i8ce4c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=452&fit=crop&dpr=1 754w, https://images.theconversation.com/files/266779/original/file-20190401-177196-i8ce4c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=452&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/266779/original/file-20190401-177196-i8ce4c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=452&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The major sources of riverine input of plastic material into the Indian Ocean.</span>
<span class="attribution"><a class="source" href="https://www.theoceancleanup.com/sources/">The Ocean Cleanup</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>The Indian Ocean has many unique characteristics compared with the other ocean basins. The most striking factor is the presence of the Asian continental landmass, which results in the absence of a northern ocean basin and generates monsoon winds.</p>
<p>As a result of the former, there is no gyre in the Northern Indian Ocean, and so there is no garbage patch. The latter results in reversing ocean surface currents.</p>
<p>The Indian and Pacific Oceans are connected through the Indonesian Archipelago, which allows for warmer, less salty water to be transported from the Pacific to the Indian via a phenomenon called the Indonesian Throughflow (see graphic, below).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/266977/original/file-20190402-177167-er8kai.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/266977/original/file-20190402-177167-er8kai.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/266977/original/file-20190402-177167-er8kai.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=418&fit=crop&dpr=1 600w, https://images.theconversation.com/files/266977/original/file-20190402-177167-er8kai.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=418&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/266977/original/file-20190402-177167-er8kai.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=418&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/266977/original/file-20190402-177167-er8kai.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=526&fit=crop&dpr=1 754w, https://images.theconversation.com/files/266977/original/file-20190402-177167-er8kai.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=526&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/266977/original/file-20190402-177167-er8kai.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=526&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Schematic currents and location of a leaky garbage patch in the southern Indian Ocean: Indonesian Throughflow (ITF), Leeuwin Current (LC), South Indian Counter Current (SICC), Agulhas Current (AC).</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>This connection also results in the formation of the Leeuwin Current, a poleward (towards the South Pole) current that flows alongside Australia’s west coast.</p>
<p>As a result, the Southern Indian Ocean has poleward currents on both eastern and western margins of the ocean basin.</p>
<p>Also, the South Indian Counter Current flows eastwards across the entire width of the Southern Indian Ocean, through the centre of the subtropical gyre, from the southern tip of Madagascar to Australia.</p>
<p>The African continent ends at around 35 degrees south, which provides a connection between the southern Indian and Atlantic Oceans.</p>
<h2>How to follow that rubbish</h2>
<p>In contrast to other ocean basins, the Indian Ocean is under-sampled, with only a few measurements of plastic material available. As technology to remotely track plastics does not yet exist, we need to use indirect ways to determine the fate of plastic in the Indian Ocean. </p>
<p><a href="https://agupubs.pericles-prod.literatumonline.com/doi/epdf/10.1029/2018JC014806" title="Role of Indian Ocean Dynamics on Accumulation of Buoyant Debris">We used</a> information from more than 22,000 satellite-tracked surface drifting buoys that have been released all over the world’s oceans since 1979. This allowed us to simulate pathways of plastic waste globally, with an emphasis on the Indian Ocean.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/267020/original/file-20190402-177196-jaxuy6.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/267020/original/file-20190402-177196-jaxuy6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/267020/original/file-20190402-177196-jaxuy6.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=458&fit=crop&dpr=1 600w, https://images.theconversation.com/files/267020/original/file-20190402-177196-jaxuy6.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=458&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/267020/original/file-20190402-177196-jaxuy6.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=458&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/267020/original/file-20190402-177196-jaxuy6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=576&fit=crop&dpr=1 754w, https://images.theconversation.com/files/267020/original/file-20190402-177196-jaxuy6.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=576&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/267020/original/file-20190402-177196-jaxuy6.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=576&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Global simulated concentration of floating waste after 50 years.</span>
<span class="attribution"><span class="source">Mirjam van der Mheen</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>We found that unique characteristics of the Southern Indian Ocean transport floating plastics towards the ocean’s western side, where it leaks past South Africa into the South Atlantic Ocean.</p>
<p>Because of the Asian monsoon system, the southeast trade winds in the Southern Indian Ocean are stronger than the trade winds in the Pacific and Atlantic Oceans. These strong winds push floating plastic material further to the west in the Southern Indian Ocean than they do in the other oceans.</p>
<h2>So the rubbish goes where?</h2>
<p>This allows the floating plastic to leak more readily from the Southern Indian Ocean into the South Atlantic Ocean. All these factors contribute to an ill-defined garbage patch in the Southern Indian Ocean.</p>
<figure>
<iframe src="https://player.vimeo.com/video/327706415" width="500" height="281" frameborder="0" webkitallowfullscreen="" mozallowfullscreen="" allowfullscreen=""></iframe>
<figcaption><span class="caption">Simulated concentration of floating waste over 50 years in the Indian Ocean.</span></figcaption>
</figure>
<p>In the Northern Indian Ocean our simulations showed there may be an accumulation of waste in the Bay of Bengal.</p>
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<strong>
Read more:
<a href="https://theconversation.com/missing-plastic-in-the-oceans-can-be-found-below-the-surface-37999">'Missing plastic' in the oceans can be found below the surface</a>
</strong>
</em>
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<p>It is also likely that floating plastics will ultimately end up on beaches all around the Indian Ocean, transported by the reversing monsoon winds and currents. Which beaches will be most heavily affected is still unclear, and will probably depend on the monsoon season.</p>
<p>Our study shows that the atmospheric and oceanic attributes of the Indian Ocean are different to other ocean basins and that there may not be a concentrated garbage patch. Therefore the mystery of all the missing plastic is even greater in the Indian Ocean.</p><img src="https://counter.theconversation.com/content/114439/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mirjam van der Mheen receives funding from the Australian Government Research Training Program and a CFH & EA Jenkins Postgraduate Scholarship at the University of Western Australia.</span></em></p><p class="fine-print"><em><span>Charitha Pattiaratchi receives funding from the Integrated Marine Observing System (IMOS) as part of National Collaborative Research Infrastructure Scheme (NCRIS),Fisheries Research and Development Council and The Australian Research Council.</span></em></p><p class="fine-print"><em><span>Erik van Sebille receives funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No 715386). </span></em></p>Great areas of rubbish – known as ‘garbage patches’ – are known to form in the Pacific and Atlantic oceans, but not the southern Indian Ocean. Why is that?Mirjam van der Mheen, PhD Candidate in Oceanography, The University of Western AustraliaCharitha Pattiaratchi, Professor of Coastal Oceanography, The University of Western AustraliaErik van Sebille, Associate Professor in Oceanography and Climate Change, Utrecht UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/837422017-11-15T11:33:08Z2017-11-15T11:33:08ZThe good news about plastic waste<figure><img src="https://images.theconversation.com/files/194362/original/file-20171113-27595-y0bmiz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">vchal/Shutterstock.com</span></span></figcaption></figure><p>Waste plastics contaminate our food, water and air. Many are <a href="http://www.plasticpollutioncoalition.org">calling</a> for a <a href="https://www.youtube.com/watch?v=-nnnHuQqeyY">global ban</a> on single-use plastics because throwing them “away” often means into our river systems and then into the <a href="https://www.theoceancleanup.com/sources/">world’s oceans</a>.</p>
<p>Take the UK’s single-use plastic bottles: it’s estimated that <a href="https://www.recyclenow.com/news/2016-10-17-britain-fails-recycle-16-million-plastic-bottles-every-day">35m</a> are used – and discarded – each day, but only 19m are recycled. The <a href="https://www.recyclenow.com/news/2016-10-17-britain-fails-recycle-16-million-plastic-bottles-every-day">16m</a> bottles that aren’t recycled go to incinerators, landfill or the environment, even though, being PET (polyethylene terephthalate) they are easily reprocessed. Even those bottles that are placed in the recycle stream may be shipped to Asia, in a global market for waste plastics that is itself leaky.</p>
<p>It’s suspected that much of the “recycling” shipped to Asia may be joining local waste in the <a href="https://www.nationalgeographic.org/encyclopedia/great-pacific-garbage-patch/">Great Pacific Garbage Patch</a>. This soupy collection of plastic debris is trapped in place by ocean currents, slowly breaking into ever-smaller pieces, but never breaking down. Covered by bacterial plaques, they are mistaken for food by fish. Ingested, they contaminate the food chain and, potentially, may even be disrupting the biophysical systems that keep our oceans stable, thus <a href="https://www.algalita.org/plastic-ocean-debris-a-driver-of-climate-change/">contributing to climate change</a>.</p>
<p>So we need to use far less plastic, re-use what we can, and dispose of what we must far more wisely. In facing this challenge, developed countries can learn from innovations in the less-developed world. People, globally, are innovating, creating new processes to use waste plastics and making new objects and art forms.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/LwcWN5znb_Q?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<h2>Filipino plastics</h2>
<p>The Philippines, for example, is the world’s third biggest plastic polluter. Waste material, even from municipal collections, makes its way into the river systems and, from there, out into the open Pacific, contributing to its “plastic soup”. But it’s largely what happens on land that determines the load the oceans must bear. </p>
<p>Industrial recycling isn’t accessible to most people in the Philippines. Even if recycling were available, shipping their waste to China, long the centre of the global plastics recycling industry, is no longer a viable option: the industry is now the target of <a href="https://www.deviantworld.com/world/politics/china-bans-foreign-waste-recycling">regulation</a> by the Chinese government, eager to <a href="https://www.plasticchina.org">clean up</a> its own environment. </p>
<p>Some waste in the Philippines is reprocessed locally. But people living in remote, rural areas have a stark choice. Either they bury their plastic waste locally, burn it, or come up with innovative solutions to repurpose the material instead. Given the unpalatable nature of the first two options, the country now has an innovative, artisanal <a href="https://www.rappler.com/move-ph/185969-action-figure-toymaker-tsinelas">plastic craft movement</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/194579/original/file-20171114-27579-6n5p1l.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/194579/original/file-20171114-27579-6n5p1l.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/194579/original/file-20171114-27579-6n5p1l.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/194579/original/file-20171114-27579-6n5p1l.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/194579/original/file-20171114-27579-6n5p1l.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/194579/original/file-20171114-27579-6n5p1l.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/194579/original/file-20171114-27579-6n5p1l.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Made from single-use plastic juice packs, this traditional Filipino blouse is a work of art.</span>
<span class="attribution"><span class="source">Villia Jefremovas</span></span>
</figcaption>
</figure>
<p>A few years ago, I worked with craftspeople and artists to put together <a href="http://lifestyle.inquirer.net/48955/cool-everyday-objects-bridge-old-new-in-the-cordillera/">an exhibition</a> of repurposed plastic waste. The items that really stood out were those things that local people made according to traditional patterns. These were items people used for cultural events that marked their identity as tribal Filipinos. Much of the work of experimentation with the materials was happening in kitchens and workplaces as people shared techniques and tips with each other.</p>
<p>One of our contributing craftspeople, Ikkay, lives in a remote tribal village in Kalinga Province. She makes strands of plastic beads out of bits of waste plastic, using old CD cases and fast food spoons – anything with a bit of gloss. Her beads are replicas of traditional tribal designs. These beads are used in local cultural performances and shipped all over the world for demonstrations of Filipino dance. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/194569/original/file-20171114-27635-1tan5qv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/194569/original/file-20171114-27635-1tan5qv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/194569/original/file-20171114-27635-1tan5qv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/194569/original/file-20171114-27635-1tan5qv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/194569/original/file-20171114-27635-1tan5qv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/194569/original/file-20171114-27635-1tan5qv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/194569/original/file-20171114-27635-1tan5qv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Kalinga dancers performing in handcrafted plastic beads.</span>
<span class="attribution"><span class="source">Villia Jefremovas</span></span>
</figcaption>
</figure>
<p>Another example of creative re-purposing came from the nearby gold mines. There, mine workers weave the yellow, red and pink plastic wrappers of blasting cap detonators into traditional basket forms. They find the high quality wrappers just as good as the rattan they’d originally used. Burly mineworkers walking the roads with dainty pink-and-yellow plastic backpacks have become a frequent site in and around mining communities. </p>
<p>In both these examples – beads and backpacks – people had figured out innovative ways to re-purpose waste plastic. They took material that would have been garbage and turned it into an item that expressed important cultural values, making something cool, fun, and desirable. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/191426/original/file-20171023-1748-136r929.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/191426/original/file-20171023-1748-136r929.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/191426/original/file-20171023-1748-136r929.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=448&fit=crop&dpr=1 600w, https://images.theconversation.com/files/191426/original/file-20171023-1748-136r929.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=448&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/191426/original/file-20171023-1748-136r929.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=448&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/191426/original/file-20171023-1748-136r929.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=563&fit=crop&dpr=1 754w, https://images.theconversation.com/files/191426/original/file-20171023-1748-136r929.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=563&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/191426/original/file-20171023-1748-136r929.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=563&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Blasting cap wrapper backpack, modelled by its producer, a former mineworker.</span>
<span class="attribution"><span class="source">ee</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The material itself – waste plastic – has something to do with this. In these Filipino cases, it made tribal displays of beads extra impressive. The makers and wearers of these items were not just subverting ideas about waste, but about social hierarchies and the social power to innovate and set trends. People who admired the plastic craft started to see plastic no longer as just “stuff” on its way to being garbage. Instead, it became imbued with the potential to become something new and different and a way of asserting local ingenuity and identity in a global world.</p>
<h2>Flip-flops and whales</h2>
<p>These examples from the Philippines are not isolated ones. Around the world, there are many small-scale groups doing very similar kinds of projects with re-purposed plastic waste. <a href="https://www.facebook.com/RehashTrash/">Rehash Trash</a> in Phnom Penh, Cambodia, makes baskets out of used plastic bags. <a href="http://oceansole.co.ke">Ocean Sole</a> in Kenya works with discarded plastic flip-flops to make art. Other initiatives are networks, like that created by <a href="https://preciousplastic.com/">Precious Plastic</a> a 3D printing initiative from Amsterdam. They have groups all over the world building 3D printers to create re-purposed plastic items for local markets.</p>
<p>In the UK, people have used fine art to communicate the urgency of the issue to the wider public, whether it’s a <a href="https://news.sky.com/video/plastic-whale-sets-off-on-ocean-rescue-campaign-10990505">giant plastic whale</a> touring the UK or the artist Stuart Haygarth’s <a href="http://www.stuarthaygarth.com/works/#/strand2012/">collection</a> of plastic waste from UK beaches, hanging in University College Hospital London. But pointing out the problem is only the first step in providing comprehensive solutions. We need to reduce our plastics footprint, seek out items made from recycled materials, and – most importantly – learn, hands on, about new ways to reuse what is now a ubiquitous class of waste materials.</p>
<p>People are meeting the challenges plastic waste poses in creative ways. While the end goal will be to phase out the materials creating the bulk of the pollution, in the meantime we must improve the capture of recycling systems globally and make locally recycled and re-purposed materials more desirable and acceptable. Learning to love plastic – wisely – means taking on the responsibility for our own discarded items. </p>
<p>We could take up the examples of these local innovation workshops and 3D printing groups to get making in communities worldwide. While making new items won’t halt the consumption of plastics altogether, it will divert material from the waste stream while helping people to see its potential. Offering the public a chance to co-create part of the solution should make the inevitable regulatory responses - deposits, disposal taxes and more rigorous waste sorting - more acceptable. </p>
<p>After all, waste plastic is still plastic and amazing stuff – you can make it into pretty much anything you can imagine.</p><img src="https://counter.theconversation.com/content/83742/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Deirdre McKay receives funding from the Arts and Humanities Research Council and the British Council Newton Agham Fund. Her Everyday Objects project was funded by the British Academy. She is currently working with Lei Xiaoyu from B Arts, an arts charity in Stoke-on-Trent, to run plastic 'making' workshops to repurpose waste plastics.</span></em></p>Everyone knows that plastic waste is an environmental problem. So let’s get creative with it.Deirdre McKay, Senior Lecturer in Geography, Keele UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/808112017-07-17T04:34:27Z2017-07-17T04:34:27ZPristine paradise to rubbish dump: the same Pacific island, 23 years apart<figure><img src="https://images.theconversation.com/files/178219/original/file-20170714-14306-wmgjzv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The same beach on Henderson Island, in 1992 and 2015.</span> </figcaption></figure><p>A few weeks ago, the world woke to the story of Henderson Island, the “<a href="https://theconversation.com/this-south-pacific-island-of-rubbish-shows-why-we-need-to-quit-our-plastic-habit-77860">South Pacific island of rubbish</a>”. Our research revealed it as a place littered with plastic garbage, washed there by ocean currents. </p>
<p>This was a story we had been waiting to tell for more than a year, keeping our discoveries under wraps while we worked our way through mountains of data and photographs. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/CKSTFOibgvQ?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Our May 2017 video story detailing the rubbish on Henderson Island.</span></figcaption>
</figure>
<p>Everyone wanted to know how the plastic got there, and fortunately that is a question that our understanding of ocean currents can <a href="http://www.pnas.org/content/114/23/6052.abstract">help us answer</a>. But the question we couldn’t answer was: when did it all start to go so wrong? </p>
<p>This is the million-dollar question for so many wild species and spaces – all too often we only notice a problem once it’s too big to deny, or perhaps even solve. So when did Henderson’s sad story start? The answer is: surprisingly recently.</p>
<h2>An eloquent photo</h2>
<p>During our research we had reached out to those who had previously worked on Henderson Island or in nearby areas, to gain a better understanding of what forces contributed to the enormous piles of rubbish that have floated to Henderson’s sandy beaches. </p>
<p>Then, after our research was published and the world was busy reading about 37 million plastic items washed up on a remote south Pacific island, we received an email from Professor Marshall Weisler from the University of Queensland, who had seen the news and got in touch.</p>
<p>In 1992, he had done archaeological surveys on Henderson Island. The photos he shared from that expedition provided a rare glimpse into the beginning of this chapter of Henderson Island’s story, before it became known as “garbage island”.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/178220/original/file-20170714-14254-10i1c3m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/178220/original/file-20170714-14254-10i1c3m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/178220/original/file-20170714-14254-10i1c3m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=412&fit=crop&dpr=1 600w, https://images.theconversation.com/files/178220/original/file-20170714-14254-10i1c3m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=412&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/178220/original/file-20170714-14254-10i1c3m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=412&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/178220/original/file-20170714-14254-10i1c3m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=518&fit=crop&dpr=1 754w, https://images.theconversation.com/files/178220/original/file-20170714-14254-10i1c3m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=518&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/178220/original/file-20170714-14254-10i1c3m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=518&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Henderson Island in happier times.</span>
<span class="attribution"><span class="source">Marshall Weisler</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/178221/original/file-20170714-14287-8jwo9p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/178221/original/file-20170714-14287-8jwo9p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/178221/original/file-20170714-14287-8jwo9p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/178221/original/file-20170714-14287-8jwo9p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/178221/original/file-20170714-14287-8jwo9p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/178221/original/file-20170714-14287-8jwo9p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/178221/original/file-20170714-14287-8jwo9p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/178221/original/file-20170714-14287-8jwo9p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The same stretch of beach in 2015.</span>
<span class="attribution"><span class="source">Jennifer Lavers</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>There are only 23 years between these two photos, and the transformation is terrifying – from pristine South Pacific gem to the final resting place for enormous quantities of the world’s waste. </p>
<p>Remember, this is not waste that was dumped directly by human hands. It was washed here on ocean currents, meaning that this is not just about one beach – it shows how much the pollution problem has grown in the entire ocean system in little more than two decades.</p>
<p>To us, Henderson Island was a brutal wake-up call, and there are undoubtedly other garbage islands out there, inundated and overwhelmed by the waste generated in the name of progress. Although the amount of trash on Henderson is staggering – an average of 3,570 new pieces arrive each day on one beach alone – it represents a minute fraction of the rubbish produced around the globe.</p>
<h2>Cleanup confounded</h2>
<p>In the wake of the story, the other big question we received (and one we should have seen coming) was: can I help you clean up Henderson Island? The answer is no, for a very long list of reasons – some obvious, some not.</p>
<p>To quote a brilliant colleague, what matters is this: if all we ever do is clean up, that is all we will ever do. With thousands of new plastic items washing up on Henderson Island every day, the answer is clear. </p>
<p>The solution doesn’t require travel to a remote island, only the courage to look within. We need to change our behaviour, to turn off the tap and stem the tide of trash in the ocean. Our oceans, our islands, and our planet demand, and deserve it.</p>
<p>However difficult those changes may be, what choice do we have?</p>
<h2>Prevention, not cure</h2>
<p>While grappling with the scale of the plastics issue can at times be overwhelming, there are <a href="https://www.jenniferlavers.org/tips-links">simple things you can do</a> to make a difference. The solutions aren’t always perfect, but each success will keep you, your family, and your community motivated to reduce plastic use. </p>
<p>First, ask yourself this: when did it become acceptable for something created from non-renewable petrochemicals, extracted from the depths of the Earth and shipped around the globe, to be referred to as “single use” or “disposable”? Your relationship with plastic begins with the language you use. </p>
<p>But don’t stop there: here are a couple of facts illustrating how you can challenge yourself and make a difference.</p>
<ul>
<li>Australians throw away an <a href="http://www.1millionwomen.com.au/blog/what-sustainable-alternative-plastic-toothbrushes/">estimated 30 million plastic toothbrushes</a> every year. </li>
</ul>
<p><strong>Challenge</strong>: switch to <a href="https://environmentaltoothbrush.com.au/">bamboo toothbrushes</a>, which cost just a few dollars each and are available from a range of online retailers or wholefood shops.</p>
<ul>
<li>A single bottle of typical exfoliating face or body scrub <a href="http://www.abc.net.au/news/2016-01-07/coles-woolworths-support-ban-on-microbeads-in-australia/7073674">contains 300,000 plastic microbeads</a>.</li>
</ul>
<p><strong>Challenge</strong>: switch to products that use crushed apricot kernels, coconut shell, coffee grounds, or sea salts as natural exfoliants.</p>
<p>These are only small changes, and you can undoubtedly think of many more. But we need to start turning the tide if we are to stop more pristine places being deluged with our garbage.</p><img src="https://counter.theconversation.com/content/80811/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jennifer Lavers receives funding from Detached Foundation and RACAT Foundation.</span></em></p><p class="fine-print"><em><span>Alexander Bond receives funding from The David & Lucile Packard Foundation, and the Darwin Initiative.</span></em></p>After making worldwide headlines with the story of the Pacific “garbage island”, researchers were sent a photo of the same beach, white sand free of litter, as recently as 1992.Jennifer Lavers (Métis Nation ᓲᐊᐧᐦᑫᔨᐤ), Research Scientist, Institute for Marine and Antarctic Studies, University of TasmaniaAlexander Bond, Senior Conservation Scientist, Royal Society for the Protection of BirdsLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/681102016-11-09T19:58:39Z2016-11-09T19:58:39ZThe oceans are full of plastic, but why do seabirds eat it?<figure><img src="https://images.theconversation.com/files/144722/original/image-20161106-27934-ft6vn2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Many seabird species, including the blue petrel (Halobaena caerulea), consume plastic at sea because algae on the plastic produce an odor that resembles their food sources.</span> <span class="attribution"><span class="source">J.J. Harrison</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Imagine that you are constantly eating, but slowly starving to death. Hundreds of species of marine mammals, fish, birds, and sea turtles face this risk every day when they mistake plastic debris for food. </p>
<p>Plastic debris can be found <a href="http://dx.doi.org/10.1073/pnas.1314705111">in oceans around the world</a>. Scientists have estimated that there are over <a href="http://dx.doi.org/10.1371/journal.pone.0111913">five trillion pieces of plastic weighing more than a quarter of a million tons</a> floating at sea globally. Most of this plastic debris comes from <a href="http://dx.doi.org/10.1126/science.1260352">sources on land</a> and ends up in oceans and bays due largely to poor waste management. </p>
<p>Plastic does not biodegrade, but at sea large pieces of plastic break down into increasingly smaller fragments that are easy for animals to consume. Nothing good comes to animals that mistake plastic for a meal. They may suffer from malnutrition, intestinal blockage, or slow poisoning from chemicals in or attached to the plastic. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/144923/original/image-20161107-4669-fxh1fl.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/144923/original/image-20161107-4669-fxh1fl.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/144923/original/image-20161107-4669-fxh1fl.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/144923/original/image-20161107-4669-fxh1fl.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/144923/original/image-20161107-4669-fxh1fl.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/144923/original/image-20161107-4669-fxh1fl.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/144923/original/image-20161107-4669-fxh1fl.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Many tube-nosed seabirds, like this Tristram’s storm petrel (Oceanodroma tristrami), eat plastic particles at sea because they mistake them for food.</span>
<span class="attribution"><span class="source">Sarah Youngren, Hawaii Pacific University/USFWS</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Despite the pervasiveness and severity of this problem, scientists still do not fully understand why so many marine animals make this mistake in the first place. It has been commonly assumed, but rarely tested, that seabirds eat plastic debris because it looks like the birds’ natural prey. However, in a study that my coauthors and I just published in Science Advances, <a href="http://advances.sciencemag.org/content/2/11/e1600395">we propose a new explanation</a>: For many imperiled species, marine plastic debris also produces an odor that the birds associate with food.</p>
<h2>A nose for sulfur</h2>
<p>Perhaps the most severely impacted animals are <a href="https://en.wikipedia.org/wiki/Procellariiformes">tube-nosed seabirds</a>, a group that includes albatrosses, shearwaters and petrels. These birds are pelagic: they often remain at sea for years at a time, searching for food over <a href="http://dx.doi.org/10.1038/343746a0">hundreds</a> or <a href="http://dx.doi.org/10.1073/pnas.0603715103">thousands</a> of square kilometers of open ocean, visiting land only to breed and rear their young. Many are also at risk of extinction. According to the <a href="https://www.iucn.org/">International Union for the Conservation of Nature</a>, nearly half of the approximately 120 species of tube-nosed seabirds are either threatened, endangered or critically endangered.</p>
<p>Although there are many fish in the sea, areas that reliably contain food are very patchy. In other words, tube-nosed seabirds are searching for a “needle in a haystack” when they forage. They may be searching for fish, squid, <a href="http://animals.nationalgeographic.com/animals/invertebrates/krill/">krill</a> or other items, and it is possible that plastic debris visually resembles these prey. But we believe that tells only part of a more complex story.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/145074/original/image-20161108-16707-9dfboo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/145074/original/image-20161108-16707-9dfboo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/145074/original/image-20161108-16707-9dfboo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/145074/original/image-20161108-16707-9dfboo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/145074/original/image-20161108-16707-9dfboo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/145074/original/image-20161108-16707-9dfboo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/145074/original/image-20161108-16707-9dfboo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A sooty shearwater (Puffinus griseus) takes off from the ocean’s surface in Morro Bay, California.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/mikebaird/7799807918">Mike Baird/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p><a href="http://dx.doi.org/10.1038/237404a0">Pioneering research</a> by Dr. Thomas Grubb Jr. in the early 1970s showed that tube-nosed seabirds use their powerful sense of smell, or olfaction, to find food effectively, even when heavy fog obscures their vision. Two decades later, Dr. Gabrielle Nevitt and colleagues <a href="http://dx.doi.org/10.1038/376680ao">found</a> that certain species of tube-nosed seabirds are attracted to <a href="https://en.wikipedia.org/wiki/Dimethyl_sulfide">dimethyl sulfide (DMS)</a>, a natural scented sulfur compound. DMS <a href="https://www.iop.org/activity/groups/subject/env/prize/winners/file_62067.pdf">comes from marine algae</a>, which produce a related chemical called DMSP inside their cells. When those cells are damaged – for example, when algae die, or when marine grazers like krill eat it – DMSP breaks down, producing DMS. The smell of DMS alerts seabirds that food is nearby – not the algae, but the krill that are consuming the algae. </p>
<p>Dr. Nevitt and I wondered whether these seabirds were being tricked into consuming marine plastic debris because of the way it smelled. To test this idea, my coauthors and I created a database collecting every study we could find that recorded plastic ingestion by tube-nosed seabirds over the past 50 years. This database contained information from over 20,000 birds of more than 70 species. It showed that species of birds that use DMS as a foraging cue eat plastic nearly six times as frequently as species that are not attracted to the smell of DMS while foraging. </p>
<p>To further test our theory, we needed to analyze how marine plastic debris smells. To do so, I took beads of the three most common types of floating plastic – polypropylene and low- and high-density polyethylene – and sewed them inside custom mesh bags, which we attached to two buoys off of California’s central coast. We hypothesized that algae would coat the plastic at sea, a process known as <a href="https://en.wikipedia.org/wiki/Biofouling">biofouling</a>, and produce DMS.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/144925/original/image-20161107-4669-14kzpg4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/144925/original/image-20161107-4669-14kzpg4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=458&fit=crop&dpr=1 600w, https://images.theconversation.com/files/144925/original/image-20161107-4669-14kzpg4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=458&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/144925/original/image-20161107-4669-14kzpg4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=458&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/144925/original/image-20161107-4669-14kzpg4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=575&fit=crop&dpr=1 754w, https://images.theconversation.com/files/144925/original/image-20161107-4669-14kzpg4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=575&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/144925/original/image-20161107-4669-14kzpg4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=575&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Author Matthew Savoca deploys experimental plastic debris at a buoy in Monterey Bay, California.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>After the plastic had been immersed for about a month at sea, I retrieved it and brought it to a lab that is not usually a stop for marine scientists: <a href="http://robertmondaviinstitute.ucdavis.edu/">the Robert Mondavi Institute for Food and Wine Science</a> at UC Davis. There we used a gas chromatograph, specifically built to detect sulfur odors in wine, beer and other food products, to measure the chemical signature of our experimental marine debris. Sulfur compounds have a very distinct odor; to humans they smell like rotten eggs or decaying seaweed on the beach, but to some species of seabirds DMS smells delicious! </p>
<p>Sure enough, every sample of plastic we collected was coated with algae and had substantial amounts of DMS associated with it. We found levels of DMS that were higher than normal background concentrations in the environment, and well above levels that tube-nosed seabirds can detect and use to find food. These results provide the first evidence that, in addition to looking like food, plastic debris may also confuse seabirds that hunt by smell. </p>
<h2>When trash becomes bait</h2>
<p>Our findings have important implications. First, they suggest that plastic debris may be a more insidious threat to marine life than we previously believed. If plastic looks and smells like food, it is more likely to be mistaken for prey than if it just looks like food. </p>
<p>Second, we found through data analysis that small, secretive burrow-nesting seabirds, such as prions, storm petrels, and shearwaters, are more likely to confuse plastic for food than their more charismatic, surface-nesting relatives such as albatrosses. This difference matters because populations of hard-to-observe burrow-nesting seabirds are more difficult to count than surface-nesting species, so they often are not surveyed as closely. Therefore, we recommend increased monitoring of these less charismatic species that may be at greater risk of plastic ingestion. </p>
<p>Finally, our results provide a deeper understanding for why certain marine organisms are inexorably trapped into mistaking plastic for food. The patterns we found in birds should also be investigated in other groups of species, like fish or sea turtles. Reducing marine plastic pollution is a <a href="http://ehp.niehs.nih.gov/123-a90/#r2">long-term, large-scale challenge</a>, but figuring out why some species continue to mistake plastic for food is the first step toward finding ways to protect them.</p><img src="https://counter.theconversation.com/content/68110/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Matthew Savoca receives funding from the National Science Foundation. </span></em></p>Thousands of seabirds die every year from consuming plastic trash in the oceans. But why do they eat plastic? New research shows that it produces odors that help some species find prey.Matthew Savoca, Ph.D. Candidate, University of California, DavisLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/595992016-06-05T20:11:51Z2016-06-05T20:11:51ZContainer deposit schemes work: so why is industry still opposed?<figure><img src="https://images.theconversation.com/files/125060/original/image-20160603-23293-1udftjv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Drink containers are the biggest contributors to rubbish in Australia.</span> <span class="attribution"><span class="source">Litter image from www.shutterstock.com</span></span></figcaption></figure><p>Australians are serial wasters. For every 1,000 square metres (or about four tennis courts), Australians litter about <a href="http://kab.org.au/wp-content/uploads/2012/05/NLI-_Summary_2015_web.pdf">49 pieces of rubbish</a>. The biggest culprits are drink containers, making up <a href="http://kab.org.au/wp-content/uploads/2012/05/NLI-_Summary_2015_web.pdf">five of the top nine</a> recorded pieces of litter by volume.</p>
<p>One way to reduce this litter is to refund people when they deposit drink containers for recycling through <a href="http://www.epa.sa.gov.au/environmental_info/container_deposit">container deposit recycling (CDR) schemes</a>.
South Australia and the Northern Territory have CDR schemes. In May this year, New South Wales Premier Mike Baird announced a <a href="http://www.epa.nsw.gov.au/waste/container-deposit-scheme.htm">CDR scheme</a> for his state, to begin in July 2017.</p>
<p>Under the scheme most drink containers over 150ml will be eligible for a 10c refund through state-wide depots and reverse vending machines. This has re-ignited an <a href="http://www.smh.com.au/environment/greenpeace-targets-cocacola-amatil-as-container-deposit-scheme-decision-looms-20160215-gmuk5p.html">ongoing debate</a>, largely driven by the drinks industry, which – as previously debated on <a href="https://theconversation.com/spin-the-bottle-the-fraught-politics-of-container-deposit-schemes-37981">The Conversation</a> - vociferously opposes these schemes.</p>
<h2>Refunds work</h2>
<p>As part of the NSW process, we at BehaviourWorks Australia at Monash University recently reviewed research and data from 47 examples of CDR schemes or trials around the world. This work was commissioned by, but independent of, the NSW Environment Protection Authority. </p>
<p>The 47 CDR schemes recovered an average of 76% of drink containers. In the United States, beverage container recovery rates for aluminium, plastic and glass in the 11 CDR states are <a href="http://org2.salsalabs.com/o/7377/p/salsa/web/common/public/signup?signup_page_KEY=8322">84%, 48% and 65% respectively, compared with 39%, 20% and 25% in non-CDR states</a>. The figures are similar in South Australia, one of the longest-running CDR schemes in the world: <a href="http://www.recyclesa.com.au/index.html">84%, 74% and 85% for cans, plastic and glass compared with national averages of 63%, 36% and 36%</a>.</p>
<p>Some CDR schemes donate the refund to charity, but people are more likely to return a container for a refund. And the greater the refund, the greater the return rates. Most schemes refund 5-10c; the 11 schemes in Canadian provinces include those with refund rates as high as <a href="http://www.bottlebill.org/legislation/canada/saskatchewan.htm">40c for glass containers over 1 litre in Saskatchewan</a>. </p>
<p>CDR schemes reduce litter overall. Data from seven US states show <a href="http://www.bottlebill.org/legislation/usa.htm">69–83% reductions in container waste and 30–47% reductions in overall waste</a>.</p>
<p>Finally, government CDR schemes are sustainable. The 40 government schemes worldwide have operated for an average of 24.8 years and all except two are still going.</p>
<h2>Industry opposition</h2>
<p>CDR schemes work, so why do they face continued opposition from the drinks industry? </p>
<p>The first major argument against is <a href="http://www.smh.com.au/nsw/nsw-cabinet-to-consider-container-deposit-scheme-20141214-126ufg.html">cost</a> – to the public, to producers, to jobs and to government via, for example, a reduction in <a href="http://www.jstor.org/stable/30000299?seq=1#page_scan_tab_contents">alcohol tax revenues due to reduced sales</a>. </p>
<p>We found little published evidence to support these claims. The few studies identified were either <a href="http://www.jstor.org/stable/30000299?seq=1#page_scan_tab_contents">funded by the beverage industry</a> or theoretical arguments <a href="http://www.jstor.org/stable/25603070?seq=1#page_scan_tab_contents">without any empirical data</a>. <a href="http://www.epa.nsw.gov.au/resources/waste/container/cds-suppliers-retailers-160281.pdf">Manufacturers and consumers will share</a> the costs of the NSW CDR scheme, with consumers paying an estimated <a href="http://www.epa.nsw.gov.au/resources/waste/container/cds-consumers-160278.pdf">A$30 into the scheme annually</a> should they not redeem any deposits.</p>
<p>The most robust cost data, the <a href="http://www.environment.gov.au/protection/nepc/publications/packaging-impacts-decision-ris">Packaging Impacts Decision Regulation Impact Statement</a>, was prepared for the Australian government in 2014. This found that CDR schemes were more expensive than other packaging recovery and recycling options, but reduced litter the most.</p>
<p>The question of whether the cost is worth the return is an important aspect of the debate, and one that should be considered not just by the beverage industry but by all stakeholders, including the wider community.</p>
<h2>Can industry do the job?</h2>
<p>The second argument against government CDR schemes is that industry can <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1748-5991.2009.01063.x/abstract">recycle containers itself</a>. Examples to support this argument are sparse and unconvincing. </p>
<p>In 2010, Coca-Cola launched a reverse vending machine scheme in Dallas Fort-Worth, Texas, with a target of 3 million beverage containers recycled per month. The scheme <a href="http://resource-recycling.com/node/5392">folded in October 2014</a>, having achieved roughly a quarter of this target.</p>
<p>PepsiCo’s ongoing Dream Machine initiative of college-based reverse vending machines commenced in April 2010 with the goal of increasing the US beverage container recycling rate from 34% to 50% by 2018. It reported collection of over 93 million containers by 2012. Although an impressive-sounding yield, achieving the target of a 50% recycling rate would require multiplying this effort <a href="http://resource-recycling.com/node/2684">400-fold</a>. </p>
<p>These examples illustrate that industry-based CDR schemes appear either unsustainable or lack realistic targets.</p>
<h2>Replacing recycling?</h2>
<p>Thirdly, it is <a href="http://reep.oxfordjournals.org/content/6/2/190.full.pdf">argued</a> that CDR schemes will cannibalise existing kerbside recycling programs. The <a href="http://reep.oxfordjournals.org/content/6/2/190.full.pdf">evidence</a> suggests that the effect, if any, is the reverse – marginal increases in kerbside recycling have been noted following introduction of CDR legislation. </p>
<p>This may be linked to the “<a href="https://theconversation.com/simple-steps-to-save-the-environment-may-not-make-much-difference-6507">spillover effect</a>” where people are more likely to do one thing if they are already doing something similar. The data from CDR schemes suggest that people may be more inclined to use kerbside recycling simply by buying a drink with a container deposit, not just getting the refund. As an example, South Australia’s overall recycling rate in 2008–2009 was <a href="https://www.environment.gov.au/protection/national-waste-policy/publications/waste-and-recycling-australia-2011">67%, against a national average of 51%</a>.</p>
<p><a href="http://www.sciencedirect.com/science/article/pii/S0921344914001797">Behavioural research</a> also tells us that convenience is a major factor in CDR schemes, particularly how close collections are to people’s homes. Vending machines are perceived as convenient but data on whether they work are <a href="http://www.eunomia.co.uk/reports-tools/a-scottish-deposit-refund-system/">mixed</a>.</p>
<p>There is also robust <a href="http://www-personal.umich.edu/%7Eprestos/Downloads/DC/pdfs/Krupka_Oct13_Cialdinietal1990.pdf">evidence</a> that clean environments are likely to remain cleaner (than otherwise would be the case) and that littered environments are likely to attract more litter.</p>
<p>This underlines the findings from research that CDR schemes not only increase beverage container recycling, but reduce litter. Ongoing CDR debate should be informed by research evidence and involve all stakeholders in this multifaceted issue.</p><img src="https://counter.theconversation.com/content/59599/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>BehaviourWorks Australia received funding for this commissioned review from the NSW Environment Protection Authority. This funding was paid to Monash University, not any of the authors personally. </span></em></p><p class="fine-print"><em><span>BehaviourWorks Australia received funding for this commissioned review from the NSW Environment Protection Authority. This funding was paid to Monash University, not any of the authors personally.</span></em></p>Refunds for drink bottles and cans get litter out of the environment – but industry remains opposed.Peter Bragge, Senior Research Fellow, Healthcare Quality Improvement (QI) at Behaviour Works, Monash UniversityBreanna Wright, Research fellow, Monash UniversityLiam Smith, Director, BehaviourWorks, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/519742016-01-07T11:16:44Z2016-01-07T11:16:44ZFar more microplastics floating in oceans than thought<figure><img src="https://images.theconversation.com/files/105537/original/image-20151211-8291-1rt4fgd.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Microplastics sample collected in a plankton net trawl in the North Pacific subtropical gyre from the SSV Robert C Seamans.</span> <span class="attribution"><span class="source">Giora Proskurowski/Sea Education Association</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Plastic pollution in the ocean frequently appears as seabird guts filled with cigarette lighters and bottle caps, marine mammals entangled in fishing gear and drifting plastic bags mimicking a gelatinous meal. Last year, <a href="http://www.sciencemag.org/lookup/doi/10.1126/science.1260352">a study</a> estimated that around eight million metric tons of our plastic waste enter the oceans from land each year.</p>
<p>But where this plastic ends up and what form it takes is a mystery. Most of our waste consists of everyday items such as bottles, wrappers, straws or bags. Yet the vast majority of debris found floating far offshore is much smaller: it’s broken-down fragments smaller than your pinky fingernail, termed microplastic. </p>
<p>In a <a href="http://iopscience.iop.org/article/10.1088/1748-9326/10/12/124006;jsessionid=123F0E078E457FC6106D3ACEE956F209.c3.iopscience.cld.iop.org">newly published study</a>, we showed that this floating microplastic accounts for only about 1% of the plastic waste entering the ocean from land in a single year. To get this number – estimated to be between 93,000 and 236,000 metric tons – we used all available measurements of floating microplastic together with three different numerical ocean circulation models.</p>
<h2>Getting a bead on microplastics</h2>
<p>Our new estimate of floating microplastic is up to 37 times higher than previous estimates. That’s equivalent to the mass of more than 1,300 blue whales. </p>
<p>The increased estimate is due in part to the larger data set – we assembled more than 11,000 measurements of microplastics collected in plankton nets since the 1970s. In addition, the data were standardized to account for differences in sampling conditions. </p>
<p>For example, <a href="http://onlinelibrary.wiley.com/doi/10.1029/2012GL051116/full">it has been shown that</a> trawls carried out during strong winds tend to capture fewer floating microplastics than during calm conditions. That’s because winds blowing on the sea surface create turbulence that pushes plastics down to tens of meters depth, out of reach of surface-trawling nets. Our statistical model takes such differences into account.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/105120/original/image-20151209-15558-w765b2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/105120/original/image-20151209-15558-w765b2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/105120/original/image-20151209-15558-w765b2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=463&fit=crop&dpr=1 600w, https://images.theconversation.com/files/105120/original/image-20151209-15558-w765b2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=463&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/105120/original/image-20151209-15558-w765b2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=463&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/105120/original/image-20151209-15558-w765b2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=582&fit=crop&dpr=1 754w, https://images.theconversation.com/files/105120/original/image-20151209-15558-w765b2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=582&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/105120/original/image-20151209-15558-w765b2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=582&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Maps of three model solutions for the amount of microplastics floating in the global ocean as particle counts (left column) and as mass (right column). Red colors indicate the highest concentrations, while blue colors are the lowest.</span>
<span class="attribution"><span class="source">van Sebille et al (2015)</span></span>
</figcaption>
</figure>
<p>The broad range in our estimates (93 to 236 thousand metric tons) stems from the fact that vast regions of the ocean have not yet been sampled for plastic debris. </p>
<p>It is widely understood that the largest concentrations of floating microplastics occur in subtropical ocean currents, or <a href="http://education.nationalgeographic.org/encyclopedia/ocean-gyre/">gyres</a>, where surface currents converge in a kind of oceanographic “dead-end.” </p>
<p>These so-called “garbage patches” of microplastics have been well-documented with data in the North Atlantic and North Pacific oceans. Our analysis includes additional data in less sampled regions, providing the most comprehensive survey of the amount of microplastic debris to date. </p>
<p>However, very few surveys have ever been carried out in the Southern Hemisphere oceans and outside of the subtropical gyres. Small differences in the oceanographic models give vastly different estimates of microplastic abundance in these regions. Our work highlights where additional ocean surveys must be done in order to improve microplastics assessments.</p>
<h2>And the rest?</h2>
<p>Floating microplastics collected in plankton nets are the best-quantified type of plastic debris in the ocean, in part because they were initially noted by researchers collecting and studying plankton decades ago. Yet microplastics represent just part of the total amount of plastic now in the ocean.</p>
<p>After all, “plastics” is a collective term for a variety of synthetic polymers with variable material properties, including density. This means some common consumer plastics, such as PET (resin code #1, stamped on the bottom of clear plastic drink bottles, for example), are denser than seawater and will sink upon entering the ocean. However, measuring plastics on the seafloor is very challenging in shallow waters close to shore, let alone across vast ocean basins with an average depth of 3.5 kilometers. </p>
<p>It’s also unknown how much of the eight million metric tons of plastic waste entering the marine environment each year lies on beaches as discarded items or broken-down microplastics. </p>
<p>In a one-day cleanup of beaches around the world in 2014, <a href="http://www.oceanconservancy.org/our-work/marine-debris/2014-by-the-numbers.html">International Coastal Cleanup</a> volunteers collected more than 5,500 metric tons of trash, including more than two million cigarette butts and hundreds of thousands of food wrappers, drink bottles, bottle caps, drinking straws and plastic bags. </p>
<p>We do know that these larger pieces of plastics will eventually become microparticles. Still, the time it takes large objects – including consumer products, buoys and fishing gear, for example – to fragment to millimeter-sized pieces upon exposure to sunlight is essentially unknown. </p>
<p>Just how small those pieces become before (or if) they are degraded by marine microorganisms is even less certain, in large part because of the difficulty in collecting and identifying microscopic particles as plastics. Laboratory and field experiments exposing different plastics to environmental weathering will help unravel the fate of different plastics in the ocean.</p>
<h2>Why it matters</h2>
<p>If we know that a massive amount of plastic is entering the ocean each year, what does it matter if it is a bottle cap on a beach, a lost lobster trap on the seafloor, or a nearly invisible particle floating thousands of miles offshore? If plastic trash were simply an aesthetic problem, perhaps it wouldn’t. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/105118/original/image-20151209-15552-13fy67.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/105118/original/image-20151209-15552-13fy67.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/105118/original/image-20151209-15552-13fy67.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/105118/original/image-20151209-15552-13fy67.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/105118/original/image-20151209-15552-13fy67.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/105118/original/image-20151209-15552-13fy67.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/105118/original/image-20151209-15552-13fy67.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Stellar sea lion with severe entanglement neck injury observed east of Vancouver Island in 2014.</span>
<span class="attribution"><span class="source">Wendy Szaniszio</span></span>
</figcaption>
</figure>
<p>But ocean plastics pose a threat to a wide variety of marine animals, and their risk is determined by the amount of debris an animal encounters, as well as the size and shape of the debris.</p>
<p>To a curious seal, an intact packing band, a loop of plastic used to secure cardboard boxes for shipping, drifting in the water is a serious entanglement hazard, whereas bits of floating microplastic might be ingested by large filter-feeding whales down to nearly microscopic zooplankton. Until we know where the millions of tons of plastics reside in the ocean, we can’t fully understand the full suite of its impacts on the marine ecosystem.</p>
<p>Yet we don’t have to wait for more research before working on solutions to this pollution problem. For the few hundred thousand tons of microplastic floating in the ocean, we know that it is not feasible to clean up these nearly microscopic particles distributed across thousands of kilometers of the sea surface. Instead, we have to turn off the tap and prevent this waste from entering the ocean in the first place.</p>
<p>In the short term, effective waste collection and waste management systems must be put in place where they are <a href="http://www.sciencemag.org/lookup/doi/10.1126/science.1260352">needed most</a>, in developing nations such as China, Indonesia and the Philippines where fast economic growth accompanied by increased waste is outpacing the capacity of infrastructure to manage this waste. In the longer term, we must rethink how we use plastics with respect to function and desired lifetime of products. At the end of its life, discarded plastic should be considered a resource for capture and reuse, rather than simply a disposable convenience.</p><img src="https://counter.theconversation.com/content/51974/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kara Lavender Law receives funding from the National Science Foundation and the National Oceanic and Atmospheric Administration.</span></em></p><p class="fine-print"><em><span>Erik van Sebille receives funding from the Australian Research Council and the UK Engineering and Physical Sciences Research Council. </span></em></p>New method tallies microplastics in southern oceans, yielding a total that’s 37 times higher than previous estimates.Kara Lavender Law, Research Professor of Oceanography, Sea Education AssociationErik van Sebille, Lecturer in Oceanography and Climate Change, Imperial College LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/500082015-11-03T19:09:53Z2015-11-03T19:09:53ZWhy do we tax goods and services at the same rate, when goods are so much less sustainable?<p>The <a href="http://www.bloomberg.com/ss/09/08/0805_biggest_garbage_dumps/8.htm">overflowing rubbish tips of Lagos</a>, the <a href="https://theconversation.com/redrawing-the-map-could-reveal-ocean-garbage-patch-culprits-31163">Pacific Ocean garbage patch</a>, and the huge <a href="http://content.time.com/time/photogallery/0,29307,1870162,00.html">electronic graveyard of Guiyu, China</a> might seem irrelevant to Australia’s <a href="http://www.abc.net.au/news/2015-11-02/gst-hike-would-raise-130b-modelling-shows/6903782">current debate over reforming the Goods and Services Tax</a>. Yet all three of these far-flung places are testament to the world’s incessant habit of buying stuff and then later throwing it away – and Australian consumers are just as culpable as any.</p>
<p>It is not hard to see why the world is awash with trash. In the United States, for instance, <a href="http://www.sciencedirect.com/science/article/pii/S095965260200152X">80% of all goods are non-reusable</a>, and <a href="http://www.sciencedirect.com/science/article/pii/S095965260200152X">more than 90% become waste within six weeks</a>. Australians, meanwhile, currently produce the <a href="https://books.google.com.au/books?id=VxGFCgAAQBAJ&pg=PA58&dq=Australian+household+waste+generation+2014&hl=en&sa=X&ved=0CC8Q6AEwAWoVChMI6MP5qoGeyAIVpRqmCh1awAYQ#v=onepage&q=Australian%20household%20waste%20generation%202014&f=false">second most waste per person</a> in the world. </p>
<p>The take-make-waste economy, premised on an imagined infinite supply of resources, has flooded the world’s shopping shelves with cheap, mass-produced products, designed for only a short life cycle and destined to end up as landfill or litter.</p>
<p>One response to this problem has been to promote recycling, but this fails to address the issue of household consumption itself. It has also given rise to an <a href="https://books.google.com.au/books?hl=en&lr=&id=GaJ06O6wFZUC&oi=fnd&pg=PA99&dq=the+international+%27waste+trade%27&ots=tzdj-_TC_D&sig=qNC3sxp0vzrtX4OIox4LKPJV36Y#v=onepage&q=the%20international%20'waste%20trade'&f=false">international waste trade</a> that lets affluent countries ship their recyclable waste to Asia, Africa and South America, where it can be difficult to track what happens to it. </p>
<p>What’s more, China’s <a href="http://www.pri.org/stories/2014-02-18/chinas-green-fence-cleaning-americas-dirty-recycling">recent move</a> to limit the recyclable materials it accepts shows that financial incentives are not a powerful measure in keeping recyclables out of landfill anyway.</p>
<p>Combine that with the growing <a href="http://www.sciencedirect.com/science/article/pii/S030142071300041X">volatility</a>
and <a href="https://lirias.kuleuven.be/bitstream/123456789/440014/1/paper+WP2A+%28website%29.pdf">scarcity</a> of resources used to manufacture goods, and it is clear that we need a less materialistic and less wasteful way of consuming. How can we encourage this? One way is to tax material goods at a higher rate than services. </p>
<h2>Tangible change</h2>
<p>In most countries, economic growth is [closely linked](http://www.abs.gov.au/ausstats/abs@.nsf/Lookup/by%20Subject/1370.0~2010~Chapter~Waste%20per%20person%20(6.6.3) to growth in waste generation. But <a href="http://www.eea.europa.eu/highlights/waste-prevention-decoupling-waste-generation">recent moves by the European Union</a> have shown how the two can potentially be decoupled by investing heavily in a service economy rather than one based on the consumption of tangible goods.</p>
<p>In Australia, taxable goods and services are currently grouped together under the same broad-based 10% sales tax. But with the future of the Goods and Services Tax now under debate, there is an opportunity (as pointed out by accounting firm KPMG in a <a href="http://www.kpmg.com/au/en/issuesandinsights/articlespublications/tax-reform/pages/tax-reform-kpmg-submission-to-treasury.aspx">submission to Treasury</a>) to acknowledge that not all consumption is equal. </p>
<p>Goods-based businesses are focused on selling tangible items, whereas service-based ones rely mostly on selling a good’s function. The bed in a hotel room, the landscaper’s lawnmower, and increasingly the cars of Uber drivers and other assets involved in the sharing economy – the life cycles of these goods go beyond a one-off transaction by a single consumer, creating a recurring income to the service provider along the way. They are examples of how to drive economic growth without driving up the consumption and output of raw materials.</p>
<p>Australia’s economy is already largely service-based – <a href="http://www.austrade.gov.au/digital-benchmark/growth.html#anchor7">82% of all business incomes</a> are for services rather than goods. This is fairly typical of developed economies, which have distanced themselves from the manufacturing competitiveness of China. </p>
<p>At the same time, though, these developed economies also have the highest overall goods consumption, and <a href="https://theconversation.com/au/topics/trade-agreement">international free trade agreements</a> are likely to expand the flood of cheap imported goods to Australia. </p>
<h2>Making taxes count</h2>
<p>A revamped GST should seek to nurture our future service industries, while reflecting the environmental and social burdens of consuming disposable (mostly imported) goods – not to mention the economic burden of running waste management services. Lumping goods and services together and taxing them at the same rate does not do this. </p>
<p>We are already comfortable with the idea of imposing higher taxes on items that are deemed to be harmful. Taxes on alcohol, cigarettes and luxury cars have all been successful in indicating to consumers the external costs to society of these consumption choices.</p>
<p>Sending a similar signal about the negative impacts of owning single-use goods will encourage Australians to embrace the de-materialised functional economy. Examples of similar incentives include the Swedish-based white goods manufacturer Electrolux, which offers a <a href="http://www.electroluxgroup.com/en/electrolux-offers-7000-households-free-washing-machines-1885/">“pay per wash” scheme</a> instead of consumers buying a washer outright. The decline in <a href="http://www.abc.net.au/news/2014-11-20/clay-millennials-are-driving-the-shift-away-from-cars/5906406">car purchases by the Millennials</a> and the rise of Uber and other digitally driven sharing models also show this shift in motion. </p>
<p>Splitting the GST into a goods tax and a services tax would allow more flexibility to increase the tax rate for non-necessity, single-use goods. The extra revenue could still be distributed to the states (as the current GST is), and from there to regional and local governments that deal with waste management, encouraging investment in new state-of-the-art resource recovery facilities.</p>
<p>The industrial revolution relied on a strong partnership between industry and government, with many manufacturing and production achievements made possible by government subsidies, support and infrastructure. The service revolution will require the same public policy support. </p>
<p>Yes, let’s reform the GST, but let the reform be guided by a vision of a sustainable Australia.</p><img src="https://counter.theconversation.com/content/50008/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Splitting the Goods and Services Tax in two, and taxing goods at a higher rate, would help to reflect the extra environmental damage done by products that are bought and later thrown in the rubbish.Angie Silva, Teaching Academic and PhD Candidate: Resource Management Transitions , Curtin UniversityTalia Raphaely, Lecturer, Curtin University Sustainability Policy Institute, Curtin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/467402015-08-31T20:06:16Z2015-08-31T20:06:16ZSeabirds are eating plastic litter in our oceans – but not only where you’d expect<figure><img src="https://images.theconversation.com/files/93131/original/image-20150827-368-192m6mo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Had a gutful of plastic rubbish affecting wildlife?</span> <span class="attribution"><span class="source">Britta Denise Hardesty</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Many of you may have already seen the photograph above, of an albatross carcass full of undigested plastic junk. But how representative is that of the wider issue facing seabirds?</p>
<p>To help answer that question, we carried out the first worldwide analysis of the threat posed by plastic pollution to seabird species worldwide. </p>
<p>Our study, <a href="http://www.pnas.org/cgi/doi/10.1073/pnas.1502108112">published today in Proceedings of the National Academy of Sciences</a>, found that nearly 60% of all seabird species studied so far have had plastic in their gut. This figure is based on reviewing previous reports in the scientific literature, but if we use a statistical model to infer what would be found at the current time and include unstudied species, we expect that more than 90% of seabirds have eaten plastic rubbish. </p>
<h2>Rising tide of plastic</h2>
<p>Our analysis of published studies shows that the amount of plastic in seabird’s stomachs has been climbing over the past half-century. In 1960, plastic was found in the stomachs of less than 5% of seabirds, but by 2010 this had risen to 80%. We predict that by 2050, 99% of the world’s seabird species will be accidentally eating plastic, unless we take action to clean up the oceans. </p>
<p>Perhaps surprisingly, we also found that the area with the worst expected impact is at the boundary of the Southern Ocean and the Tasman Sea, between Australia and New Zealand. While this region is far away from the subtropical gyres, dubbed “ocean garbage patches”, that collect the highest densities of plastic, the highest threat is in areas where plastic rubbish overlaps with large numbers of different seabird species – such as the Southern Ocean off Australia.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/93265/original/image-20150828-17435-140ee9d.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/93265/original/image-20150828-17435-140ee9d.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/93265/original/image-20150828-17435-140ee9d.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=413&fit=crop&dpr=1 600w, https://images.theconversation.com/files/93265/original/image-20150828-17435-140ee9d.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=413&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/93265/original/image-20150828-17435-140ee9d.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=413&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/93265/original/image-20150828-17435-140ee9d.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=519&fit=crop&dpr=1 754w, https://images.theconversation.com/files/93265/original/image-20150828-17435-140ee9d.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=519&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/93265/original/image-20150828-17435-140ee9d.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=519&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Expected number of seabird species ingesting plastic.</span>
<span class="attribution"><a class="source" href="http://www.pnas.org/cgi/doi/10.1073/pnas.1502108112">PNAS</a></span>
</figcaption>
</figure>
<p>Seabirds are excellent indicators of ecosystem health. The high estimates of plastic in seabirds we found were not so surprising, considering that members of our research team have previously found nearly 200 pieces of plastic in a single seabird. These items include a wide range of things most of us would recognise: bags, bottle caps, bits of balloons, cigarette lighters, even toothbrushes and plastic toys. </p>
<p>Seabirds can have surprising amounts of plastic in their gut. Working on islands off Australia, we have found birds with plastics making up 8% of their body weight. Imagine a person weighing 62 kg having almost 5 kg of plastic in their digestive tract. And then think about how large that lump would be, given that many types of plastic are designed to be as lightweight as possible.</p>
<p>The more plastic a seabird encounters, the more it tends to eat, which means that one of the best predictors of the amount of plastic in a seabird’s gut is the concentration of ocean plastic in the region where it lives. This finding points the way to a solution: reducing the amount of plastic that goes into the ocean would directly reduce the amount that seabirds (and other wildlife) accidentally eat. </p>
<p>That might sound obvious, but as we can see from the stomach contents of the birds, many of the items are things people use every day, so the link to human rubbish is clear. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/93410/original/image-20150831-29524-d82uzn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/93410/original/image-20150831-29524-d82uzn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/93410/original/image-20150831-29524-d82uzn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=451&fit=crop&dpr=1 600w, https://images.theconversation.com/files/93410/original/image-20150831-29524-d82uzn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=451&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/93410/original/image-20150831-29524-d82uzn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=451&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/93410/original/image-20150831-29524-d82uzn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/93410/original/image-20150831-29524-d82uzn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/93410/original/image-20150831-29524-d82uzn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Plastic from a dead flesh-footed shearwater, amounting to 8% of the bird’s body weight.</span>
<span class="attribution"><span class="source">Britta Denise Hardesty</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Our study suggests that improving waste management would directly benefit wildlife. There are several actions we could take, such as reducing packaging, banning single-use plastic items or charging an extra fee to use them, and introducing deposits for recyclable items like drink containers. </p>
<p>Many of these types of policies are already proving to be locally effective in reducing waste lost into the environment, a substantial portion of which ends up polluting the ocean. </p>
<p>One <a href="http://www.sciencedirect.com/science/article/pii/S0269749115001104">recent study</a> of industrial practices in Europe found that improved management of plastic led to a clear reduction in the number of plastic items found in seabirds in the North Sea within a few decades. This is encouraging, as it suggests not only that the solutions are effective, but also that they work in a relatively short time. </p>
<p>Given that most of these items were in someone’s hands at some point, it seems that a simple behaviour change can reduce a global impact to our seabirds, and to other marine species as well.</p>
<p><em>This work was carried out as part of a national marine debris project supported by CSIRO and Shell’s Social investment program, as well as the marine debris working group at the <a href="https://www.nceas.ucsb.edu/">US National Center for Ecological Analysis and Synthesis</a>, University of California, Santa Barbara, with support from <a href="http://www.oceanconservancy.org">Ocean Conservancy</a>.</em></p><img src="https://counter.theconversation.com/content/46740/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Chris Wilcox receives funding from CSIRO, Shell Social Investment Fund</span></em></p><p class="fine-print"><em><span>Britta Denise Hardesty received funding for this work from CSIRO and Shell’s Social investment program .</span></em></p><p class="fine-print"><em><span>Erik van Sebille receives funding from the Australian Research Council and the Engineering and Physical Sciences Research Council.</span></em></p>By 2050, 99% of the world’s seabird species will be accidentally eating plastic, unless we take action to clean up the oceans. And some of the highest risk to wildlife is in the Southern Ocean off Australia.Chris Wilcox, Senior Research Scientist, CSIROBritta Denise Hardesty, Senior Research Scientist, Oceans and Atmosphere Flagship, CSIROErik van Sebille, Lecturer in oceanography and climate change, Imperial College LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/379992015-02-26T19:45:29Z2015-02-26T19:45:29Z‘Missing plastic’ in the oceans can be found below the surface<figure><img src="https://images.theconversation.com/files/73190/original/image-20150226-1758-15sner8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Trawling for plastic at different depths.</span> <span class="attribution"><span class="source">Julia Reisser</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>The world’s ocean contains trillions of plastic fragments coming from packaging, fishing gear and other synthetic objects that break down at sea over time. </p>
<p>Most of what is known about these ocean plastics comes from surface net sampling, where the top 15cm of water is filtered to collect particles larger than 0.3mm. </p>
<p>Now we have published the first ever high-resolution depth profiles of ocean plastics in the journal <a href="http://www.biogeosciences.net/12/1249/2015/bg-12-1249-2015.html">Biogeosciences</a> and data repository <a href="http://figshare.com/articles/Data_from_The_vertical_distribution_of_buoyant_plastics_at_sea_an_observational_study_in_the_North_Atlantic_subtropical_gyre_/1308506">Figshare</a>.</p>
<p>Most of the submerged plastics were very small – less than 1 mm across. Previous studies had noticed that tiny plastics were missing from the oceans.</p>
<p>We show that at least a fraction of this missing plastic is still adrift at sea, but at depths greater than the surface layer that is usually sampled by scientists.</p>
<p>A better characterisation of the vertical distribution of marine plastic pollution will improve predictions of plastic loads, particle sizes, and ecological impacts in the world’s oceans.</p>
<h2>Vertical distribution of buoyant plastics</h2>
<p>Buoyant plastics can be pushed underwater by the turbulence created by wind and waves. <a href="http://onlinelibrary.wiley.com/doi/10.1029/2012GL051116/abstract">Models</a> predict that the number of plastic particles decreases abruptly over the first few meters of the water column. However, until now, no subsurface measurements existed to test this prediction.</p>
<p>We developed a new device that collects samples from the sea surface at 50cm intervals, down to a depth of 5 meters. This device was used to sample one of the world’s major plastic pollution hotspots: the North Atlantic “garbage patch”.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/73083/original/image-20150225-1758-1ksvsnp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/73083/original/image-20150225-1758-1ksvsnp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=310&fit=crop&dpr=1 600w, https://images.theconversation.com/files/73083/original/image-20150225-1758-1ksvsnp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=310&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/73083/original/image-20150225-1758-1ksvsnp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=310&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/73083/original/image-20150225-1758-1ksvsnp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=389&fit=crop&dpr=1 754w, https://images.theconversation.com/files/73083/original/image-20150225-1758-1ksvsnp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=389&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/73083/original/image-20150225-1758-1ksvsnp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=389&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The area sampled was within the garbage patch – however you chose to define it. Sampling device is pictured on the right.</span>
<span class="attribution"><span class="source">Reisser et al. 2015 Biogeosciences</span></span>
</figcaption>
</figure>
<p>Buoyant plastics were concentrated at the sea surface, with both numerical and mass concentrations decreasing exponentially with water depth. Nevertheless, under stronger winds this decrease was less abrupt. Our results match relatively well with those predicted by <a href="http://onlinelibrary.wiley.com/doi/10.1029/2012GL051116/abstract">scientific models</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/73082/original/image-20150225-1807-2pmo8w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/73082/original/image-20150225-1807-2pmo8w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/73082/original/image-20150225-1807-2pmo8w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=417&fit=crop&dpr=1 600w, https://images.theconversation.com/files/73082/original/image-20150225-1807-2pmo8w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=417&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/73082/original/image-20150225-1807-2pmo8w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=417&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/73082/original/image-20150225-1807-2pmo8w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=524&fit=crop&dpr=1 754w, https://images.theconversation.com/files/73082/original/image-20150225-1807-2pmo8w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=524&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/73082/original/image-20150225-1807-2pmo8w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=524&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Wind shifts plastic away from the surface, but most of the mass stays at this layer.</span>
<span class="attribution"><span class="source">Reisser et al. 2015 Biogeosciences</span></span>
</figcaption>
</figure>
<h2>Look below the sea surface</h2>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/73088/original/image-20150225-1761-zv2wgy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/73088/original/image-20150225-1761-zv2wgy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1614&fit=crop&dpr=1 600w, https://images.theconversation.com/files/73088/original/image-20150225-1761-zv2wgy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1614&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/73088/original/image-20150225-1761-zv2wgy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1614&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/73088/original/image-20150225-1761-zv2wgy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=2028&fit=crop&dpr=1 754w, https://images.theconversation.com/files/73088/original/image-20150225-1761-zv2wgy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=2028&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/73088/original/image-20150225-1761-zv2wgy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=2028&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Percentage of hard plastics of different size classes located at depths greater than 0.5 m during sampling at Beaufort scale 1, 3, and 4.</span>
<span class="attribution"><span class="source">Reisser et al. 2015 Biogeosciences</span></span>
</figcaption>
</figure>
<p>The speed in which buoyant plastics return to the sea surface after being pushed into deeper waters by turbulence is an important parameter for predicting the depth profiles of marine plastic pollution. We found that smaller plastics present lower rising speeds, being therefore more susceptible to transport into deeper layers.</p>
<p>Even under light wind conditions, many of the tiniest plastics were still hidden underwater. This indicates that previous studies using surface-only samples are biased towards larger plastic pieces. </p>
<p>Two major studies last year headed by ocean scientists
<a href="http://www.pnas.org/content/111/28/10239.abstract">Andres Cózar</a> and <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0111913">Marcus Eriksen</a> both concluded that there are major losses of small plastics from oceans. We show that at least a fraction of this “missing” plastic is just under the sea surface.</p>
<p>More at-sea and experimental work is required to further quantify this effect and develop models capable of estimating depth-integrated size distribution of buoyant plastics drifting at sea.</p>
<h2>What’s next?</h2>
<p>Samples of ocean plastics from below the surface are still very scarce. Further multi-level sampling is extremely important to help us estimate how much plastic is actually in our oceans, and understand its ecological impacts.</p>
<p>Knowing how deep plastics go will help determine the chance of animals inhabiting different depths to encounter and interact with plastic items. For instance, sea birds, turtles, and mammals, which breathe air and use the sea surface for daily activities, present high rates of plastic <a href="http://midwayfilm.com/">ingestion</a> and <a href="https://www.youtube.com/watch?v=hfuln4GssN0#t=392">entanglement</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/73103/original/image-20150225-1819-17zuizq.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/73103/original/image-20150225-1819-17zuizq.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=360&fit=crop&dpr=1 600w, https://images.theconversation.com/files/73103/original/image-20150225-1819-17zuizq.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=360&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/73103/original/image-20150225-1819-17zuizq.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=360&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/73103/original/image-20150225-1819-17zuizq.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=452&fit=crop&dpr=1 754w, https://images.theconversation.com/files/73103/original/image-20150225-1819-17zuizq.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=452&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/73103/original/image-20150225-1819-17zuizq.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=452&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Fragment of fishing net drifting at sea.</span>
<span class="attribution"><span class="source">Bryce Groark/Alamy</span></span>
</figcaption>
</figure>
<p>Ocean plastics are also enhancing ocean drift opportunities and causing damage to biota and habitats. Plastic items harbour organisms such as <a href="https://theconversation.com/creatures-living-on-tiny-ocean-plastic-may-be-cleaning-our-seas-27876">microbes, invertebrates</a> and fish, which can disperse across oceans and potentially invade non-native habitats.</p>
<p>We emphasise that estimates on the amounts and impacts of plastic pollution across the oceans, both in coastal and oceanic environments, are urgently required. Such research is crucial to better inform those aiming to <a href="http://plasticpollutioncoalition.org/">reduce the flow of plastics</a> entering this environment, and develop <a href="http://www.theoceancleanup.com/">mitigation strategies</a> for this worldwide problem.</p><img src="https://counter.theconversation.com/content/37999/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Julia Reisser received funding and support from the University of Western Australia and CSIRO Wealth from Oceans Flagship. The data reported here was collected aboard sailing vessel Sea Dragon, from Pangaea Exploration. She is now working as an oceanographer at The Ocean Cleanup Foundation.</span></em></p><p class="fine-print"><em><span>Charitha Pattiaratchi receives funding from the Intergrated Marine Observing System and Bushfire Natural Hazards Cooperative Research Centre.</span></em></p><p class="fine-print"><em><span>Maira Proietti received funding from The Rufford Foundation.</span></em></p>We dump more plastic into the ocean each year than we’ve been able to find. New research says much of it is lurking just below the waves.Julia Reisser, Oceanographer, PhD candidate researching plastic pollution and sea turtles, The University of Western AustraliaCharitha Pattiaratchi, Professor of Coastal Oceanography, The University of Western AustraliaMaira Proietti, Adjunct professor, Fundação Universidade Federal do Rio Grande (FURG)Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/375212015-02-12T20:45:26Z2015-02-12T20:45:26ZEight million tonnes of plastic are going into the ocean each year<figure><img src="https://images.theconversation.com/files/71807/original/image-20150212-16595-1yv1xnx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Plastic waste washed up on a beach in Haiti. </span> <span class="attribution"><span class="source">Timothy Townsend</span></span></figcaption></figure><p>You might have heard the oceans are full of plastic, but how full exactly? Around 8 million metric tonnes go into the oceans each year, according to the <a href="http://www.sciencemag.org/lookup/doi/10.1126/science.1260352">first rigorous global estimate</a> published in Science today. </p>
<p>That’s equivalent to 16 shopping bags full of plastic for every metre of coastline (excluding Antarctica). By 2025 we will be putting enough plastic in the ocean (on our most conservative estimates) to cover 5% of the earth’s entire surface in cling film each year.</p>
<p>Around a third of this likely comes from China, and 10% from Indonesia. In fact all but one of the top 20 worst offenders are developing nations, largely due to fast-growing economies but poor waste management systems. </p>
<p>However, people in the United States – coming in at number 20 and producing less than 1% of global waste – produce more than 2.5 kg of plastic waste each day, more than twice the amount of people in China. </p>
<p>While the news for us, our marine wildlife, seabirds, and fisheries is not good, the research paves the way to improve global waste management and reduce plastic in the waste stream. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/71658/original/image-20150211-24651-1x6m0ss.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/71658/original/image-20150211-24651-1x6m0ss.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/71658/original/image-20150211-24651-1x6m0ss.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/71658/original/image-20150211-24651-1x6m0ss.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/71658/original/image-20150211-24651-1x6m0ss.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/71658/original/image-20150211-24651-1x6m0ss.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/71658/original/image-20150211-24651-1x6m0ss.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/71658/original/image-20150211-24651-1x6m0ss.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">Lindsay Robinson/University of Georgia</span></span>
</figcaption>
</figure>
<h2>Follow the plastic</h2>
<p>An international team of experts analysed 192 countries bordering the Atlantic, Pacific and Indian Oceans, and the Mediterranean and Black Seas. By examining the amount of waste produced per person per year in each country, the percentage of that waste that’s plastic, and the percentage of that plastic waste that is mismanaged, the team worked out the likely worst offenders for marine plastic waste. </p>
<p>In 2010, 270 million tonnes of plastic was produced around the world. This translated to 275 million tonnes of plastic waste; 99.5 million tonnes of which was produced by the two billion people living within 50 km of a coastline. Because some durable items such as refrigerators produced in the past are also thrown away, we can find more waste than plastic produced at times. </p>
<p>Of that, somewhere between 4.8 and 12.7 million tonnes found its way into the ocean. Given how light plastic is, this translates to an unimaginably large volume of debris. </p>
<p>While plastic can make its way into oceans from land-locked countries via rivers, these were excluded in the study, meaning the results are likely a conservative estimate. </p>
<p>With our planet still 85 years away from “peak waste” — and with plastic production skyrocketing around the world — the amount of plastic waste getting into the oceans is likely to increase by an order of magnitude within the next decade.</p>
<p>Our <a href="https://theconversation.com/the-oceans-are-full-of-our-plastic-heres-what-we-can-do-about-it-31460">recent survey</a> of the Australian coastline found three-quarters of coastal rubbish is plastic, averaging more than 6 pieces per meter of coastline. Offshore, we found densities from a few thousand pieces of plastic to more than 40,000 pieces per square kilometre in the waters around the continent.</p>
<h2>Where is the plastic going?</h2>
<p>While we now have a rough figure for the amount of plastic rubbish in the world’s oceans, we still know very little about where it all ends up (it isn’t all in the infamous “<a href="http://response.restoration.noaa.gov/about/media/how-big-great-pacific-garbage-patch-science-vs-myth.html">Pacific Garbage Patch</a>”).</p>
<p>Between 6,350 and 245,000 metric tons of plastic waste is estimated to float on the ocean’s surface, which raises the all-important question: where does the rest of it end up?</p>
<p>Some, like the <a href="http://www.beatthemicrobead.org/en/">plastic microbeads</a> found in many personal care products, ends up in the oceans and sediments where they can be ingested by bottom-dwelling creatures and filter-feeders. </p>
<p>It’s unclear where the rest of the material is. It might be deposited on coastal margins, or maybe it breaks down into fragments so small we can’t detect it, or maybe it is in the <a href="http://www.pnas.org/content/111/28/10239.full0">guts of marine wildlife</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/71806/original/image-20150212-16611-qboitu.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/71806/original/image-20150212-16611-qboitu.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/71806/original/image-20150212-16611-qboitu.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=430&fit=crop&dpr=1 600w, https://images.theconversation.com/files/71806/original/image-20150212-16611-qboitu.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=430&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/71806/original/image-20150212-16611-qboitu.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=430&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/71806/original/image-20150212-16611-qboitu.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=541&fit=crop&dpr=1 754w, https://images.theconversation.com/files/71806/original/image-20150212-16611-qboitu.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=541&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/71806/original/image-20150212-16611-qboitu.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=541&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Plastic recovered from a dead shearwater - a glowstick, industrial plastic pellets, and bits of balloon.</span>
<span class="attribution"><span class="source">CSIRO</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Wherever it ends up, plastic has enormous potential for destruction. <a href="https://theconversation.com/ghostnets-fish-on-marine-rubbish-threatens-northern-australian-turtles-11585">Ghost nets</a> and fishing debris snag and drown turtles, seals, and other marine wildlife. In some cases, these interactions have big impacts. </p>
<p>For instance, we estimate that <a href="http://onlinelibrary.wiley.com/doi/10.1111/cobi.12355/full">around 10,000 turtles</a> have been trapped by derelict nets in Australia’s Gulf of Carpentaria region alone.</p>
<p>More than <a href="http://www.sciencedirect.com/science/article/pii/S0025326X14008571">690 marine species</a> are known to interact with marine litter. Turtles <a href="http://www.biomedcentral.com/1472-6785/14/14">mistake floating plastic for jellyfish</a>, and globally around one-third of all turtles are estimated to have <a href="http://onlinelibrary.wiley.com/doi/10.1111/cobi.12126/full">eaten plastic</a> in some form. Likewise seabirds eat everything from plastic toys, <a href="http://en.wikipedia.org/wiki/Plastic_particle_water_pollution">nurdles</a> and balloon shreds to foam, fishing floats and glow sticks. </p>
<p>While plastic is prized for its durability and inertness, it also acts as a chemical magnet for environmental pollutants such as metals, fertilisers, and persistent organic pollutants. These are adsorbed onto the plastic. When an animal eats the plastic “meal”, these chemicals make their way into their tissues and — in the case of commercial fish species — can make it onto our dinner plates. </p>
<p>Plastic waste is the scourge of our oceans; killing our wildlife, polluting our beaches, and threatening our food security. But there are solutions – some of which are simple, and some a bit more challenging.</p>
<h2>Solutions</h2>
<p>If the top five plastic-polluting countries – China, Indonesia, the Philippines, Vietnam and Sri Lanka – managed to achieve a 50% improvement in their waste management — for example by investing in waste management infrastructure, the total global amount of mismanaged waste would be reduced by around a quarter.</p>
<p>Higher-income countries have equal responsibility to reduce the amount of waste produced per person through measures such as plastic recycling and reuse, and by shifting some of the responsibility for plastic waste back onto the producers.</p>
<p>The simplest and most effective solution might be to make the plastic worth money. Deposits on beverage containers for instance, have <a href="http://www.csiro.au/Portals/Media/Plastic-on-the-coasts-is-ours.aspx">proven effective</a> at reducing waste lost into the environment – because the containers, plastic and otherwise, are worth money people don’t throw them away, or if they do others pick them up. </p>
<p>Extending this idea to a deposit on all plastics at the beginning of their lifecycle, as raw materials, would incentivize collection by formal waste managers where infrastructure is available, but also by consumers and entrepreneurs seeking income where it is not. </p>
<p>Before the plastic revolution, much of our waste was collected and burned. But the ubiquity, volume, and permanence of plastic waste demands better solutions.</p><img src="https://counter.theconversation.com/content/37521/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Britta Denise Hardesty has received funding from Shell Australia's Social Investment Program and CSIRO's Oceans and Atmosphere Flagship. </span></em></p><p class="fine-print"><em><span>Chris Wilcox has recieved funding from Shell Australia's social investment fund and CSIRO's Oceans and Atmosphere Flagship.</span></em></p>You might have heard the oceans are full of plastic, but how full exactly? Around 8 million metric tonnes go into the oceans each year, according to the first rigorous global estimate published in Science…Britta Denise Hardesty, Senior Research Scientist, Oceans and Atmosphere Flagship, CSIROChris Wilcox, Senior Research Scientist, CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/311632014-09-02T19:56:39Z2014-09-02T19:56:39ZRedrawing the map could reveal ocean garbage patch culprits<figure><img src="https://images.theconversation.com/files/58003/original/4nr84whv-1409642461.jpg?ixlib=rb-1.1.0&rect=32%2C175%2C2371%2C1575&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Rubbish strewn on beaches eventually ends up in one of the world's giant ocean garbage patches.</span> <span class="attribution"><span class="source">Vberger/Wikimedia Commons</span></span></figcaption></figure><p>Most of us have littered at one time or another, and in the process we probably contributed to the enormous of amounts of plastic that enter the ocean every year, eventually ending up in one of the five so-called <a href="https://theconversation.com/whose-job-is-it-to-clear-up-all-the-rubbish-floating-in-the-oceans-25082">ocean garbage patches</a>. </p>
<p>This plastic marine debris lingers for centuries, posing a (sometimes deadly) threat to marine life, and accumulating in growing quantities up the food chain. Yet there is very little data about where the plastic we find in our ocean comes from, and our new research redraws some of the conventional boundaries between the oceans, suggesting that litter doesn’t always go into its “local” garbage patch.</p>
<p>Working out which countries have contributed most to the marine plastics problem is a vexed issue. Nevertheless, attributing blame will be a crucial step in holding polluting countries to account, and getting them to clean up after themselves. </p>
<p>Our <a href="http://scitation.aip.org/content/aip/journal/chaos/24/3/10.1063/1.4892530">study</a>, published in the journal <em>Chaos</em>, provides a crucial piece in the puzzle of who is creating these marine dumping grounds.</p>
<h2>Rubbish round-trip</h2>
<p>If you were foolish enough to throw a plastic bottle into the ocean at the beach, it would go on a <a href="http://www.adrift.org.au">very long journey</a>. It would slowly drift with the currents until, depending on which beach you dropped it at, it would eventually find its way into one of the five ocean garbage patches. </p>
<p>By the time it made it to the garbage patch, your bottle would have been adrift for several years, and the sun and waves would have broken it down into millimetre-sized pellets. Removing all these tiny pellets from the water is <a href="https://theconversation.com/leave-the-ocean-garbage-alone-we-need-to-stop-polluting-first-13537">far more difficult than it sounds</a>.</p>
<p>The garbage patches are formed by currents that move water (and plastic) around the world in a complicated pattern. Most of that water circulates in “gyres”. There is one gyre in each ocean in each hemisphere, each with a garbage patch at its centre. Knowing which countries border which gyre is therefore an important first step in the garbage patch blame game.</p>
<p>However, ocean currents do not confine themselves to individual oceans, the borders of which were drawn up by the <a href="http://en.wikipedia.org/wiki/International_Hydrographic_Organization">International Hydrographic Organization</a> and largely reflect geopolitical boundaries.</p>
<p>For example, the “border” between the Indian and Pacific oceans is internationally recognised as a straight line running south from Tasmania. This suggests that plastic bottles thrown into the ocean east of Tasmania would end up in the South Pacific Ocean, while plastic bottles littered west of Tasmania would head to the Indian Ocean. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/57997/original/2bgfqgfp-1409637185.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/57997/original/2bgfqgfp-1409637185.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/57997/original/2bgfqgfp-1409637185.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=299&fit=crop&dpr=1 600w, https://images.theconversation.com/files/57997/original/2bgfqgfp-1409637185.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=299&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/57997/original/2bgfqgfp-1409637185.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=299&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/57997/original/2bgfqgfp-1409637185.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=376&fit=crop&dpr=1 754w, https://images.theconversation.com/files/57997/original/2bgfqgfp-1409637185.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=376&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/57997/original/2bgfqgfp-1409637185.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=376&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Conventional boundaries of the Pacific (left) and Indian (right) Oceans, as defined by the International Hydrographic Office.</span>
<span class="attribution"><span class="source">Wikipedia</span></span>
</figcaption>
</figure>
<p>Our study shows that this isn’t true. In reality, all of the Great Australian Bight, much of the Southern Ocean southwest of Australia, and even regions south of Africa, are much more closely linked to the South Pacific than to the Indian Ocean. </p>
<p>Our new map of the world’s oceans redraws ocean boundaries according to science, rather than geopolitics. These current-driven boundaries show the true catchment areas of the garbage patches.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/57996/original/6ydqy3gv-1409636973.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/57996/original/6ydqy3gv-1409636973.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/57996/original/6ydqy3gv-1409636973.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=304&fit=crop&dpr=1 600w, https://images.theconversation.com/files/57996/original/6ydqy3gv-1409636973.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=304&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/57996/original/6ydqy3gv-1409636973.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=304&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/57996/original/6ydqy3gv-1409636973.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=382&fit=crop&dpr=1 754w, https://images.theconversation.com/files/57996/original/6ydqy3gv-1409636973.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=382&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/57996/original/6ydqy3gv-1409636973.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=382&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Map of the catchment regions of the garbage patches, suggesting that the true boundaries between the oceans don’t match the internationally recognised ones. Land masses are shown in white.</span>
<span class="attribution"><span class="source">Froyland et al, Chaos, 2014.</span></span>
</figcaption>
</figure>
<h2>Blame still hard to pin down</h2>
<p>Even armed with this new knowledge, attributing blame for the different patches is not going to be easy. The currents have been mapped quite well, but not the density of the plastics throughout the ocean. </p>
<p>To find the culprits, we need to know not only where the garbage patches are, but also the distribution of the debris that is still making its years-long voyage towards the patches. If we know that, we’ll know which are the most influential currents that ferry litter around the world, and we’ll be able to trace them back to the places where people are dropping it.</p>
<p>That’s research for the future, to be done with the help of groups like <a href="http://5gyres.org">5Gyres</a>, which sample water all over the world to detect debris. </p>
<p>Meanwhile, what we can say from our new map is that countries don’t necessarily contribute garbage to their “local” ocean, according to our conventional ocean boundaries. </p>
<p>To further complicate things, our research also suggests that the garbage patches are leaky. Even though plastic accumulates in the garbage patches, it doesn’t stay there forever. We found that all patches exchange material with their neighbours to varying degrees. </p>
<p>The littering of the ocean is therefore ultimately a global problem. Given the practical difficulties of removing this litter from the oceans, and the fact that it lingers for decades, the world needs to realise that we are all in this together.</p><img src="https://counter.theconversation.com/content/31163/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Erik van Sebille receives funding from the Australian Research Council</span></em></p><p class="fine-print"><em><span>Gary Froyland receives funding from the Australian Research Council.</span></em></p>Most of us have littered at one time or another, and in the process we probably contributed to the enormous of amounts of plastic that enter the ocean every year, eventually ending up in one of the five…Erik van Sebille, Research Fellow and Lecturer in Oceanography, UNSW SydneyGary Froyland, Professor of Mathematics, ARC Future Fellow, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.